tag:theconversation.com,2011:/ca/topics/ants-112/articlesAnts – The Conversation2023-12-08T02:55:55Ztag:theconversation.com,2011:article/2189082023-12-08T02:55:55Z2023-12-08T02:55:55ZFire ants are on the march. Here’s what happens when they sting<figure><img src="https://images.theconversation.com/files/564401/original/file-20231207-28-zox765.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C998%2C666&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/red-fire-ant-1211635918">Veronika Kunitsyna/Shutterstock</a></span></figcaption></figure><p>Red imported fire ants are a particularly nasty type of ant because they are aggressive, and inflict painful stings that may be life threatening. That’s in addition to being a serious threat to <a href="https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/biosecurity/animals/invasive/restricted/fire-ant">agriculture and biosecurity</a>. </p>
<p><a href="https://www.dpi.nsw.gov.au/biosecurity/insect-pests/fire-ants">In recent weeks</a>, we heard these ants <a href="https://www.outbreak.gov.au/current-outbreaks/red-imported-fire-ant">had spread</a> from Queensland, south into northern New South Wales.</p>
<p>Although their stings are rare in Australia, they can lead to a serious allergic reaction. Here’s what to do if you’ve been stung.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/why-red-fire-ants-and-yellow-crazy-ants-have-given-themselves-a-green-light-to-invade-australia-208479">Why red fire ants and yellow crazy ants have given themselves a green light to invade Australia</a>
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<h2>Which ants are we talking about?</h2>
<p>Red imported fire ants (<em>Solenopsis invicta</em>) are native to South America but have been <a href="https://www.ncbi.nlm.nih.gov/books/NBK470576/">spreading across the world</a> in contaminated soil.</p>
<p><a href="https://www.dpi.nsw.gov.au/biosecurity/insect-pests/fire-ants">The ants</a> are 2-6 millimetres long and are a dark red-brown colour. They live in nests in the ground. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/_XL6QWRHZes?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Here’s what red imported fire ants look like (Biosecurity Queensland).</span></figcaption>
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<p>When a nest is disturbed, hundreds of ants come out and attack. Their jaws lock onto the skin and they arch their body to <a href="https://www.ncbi.nlm.nih.gov/books/NBK470576/">inject venom</a> through a stinger on their abdomen. Each ant stings an average <a href="https://www.ncbi.nlm.nih.gov/books/NBK470576/">seven to eight times</a>.</p>
<p>These ants sting <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8151706/">millions of people</a> a year in the United States.</p>
<p>Anyone who disturbs their nest is at risk of being stung. Even minor disturbances will cause the ants to surface and attack.</p>
<p>Overseas, people have been stung by ants that have <a href="https://pubmed.ncbi.nlm.nih.gov/37355195/">formed rafts</a> during heavy rainfall and flooding.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/from-deadly-jaws-and-enormous-strength-to-mushroom-farming-ant-man-is-only-tapping-into-a-portion-of-the-real-superpowers-of-ants-200530">From deadly jaws and enormous strength to mushroom farming, Ant-Man is only tapping into a portion of the real superpowers of ants</a>
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<h2>What happens when this ant stings you?</h2>
<p>Fortunately, red imported fire ant stings have been uncommon in Australia, and we hope it stays this way.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/books/NBK470576/">Their sting</a> is painful, with a fire-like burning character, and is associated with swelling and redness. Over the following hours or days, sting sites develop blisters or pustules that are itchy and take days to improve. </p>
<p>A person can easily be stung hundreds of times, which can cause a lot of distress.</p>
<h2>What’s the treatment? Do I need to go to hospital?</h2>
<p>Many people with a smaller number of stings can be safely managed at home. <a href="https://www.healthdirect.gov.au/insect-bites-and-stings">Usual treatments</a> <a href="https://www.poisonsinfo.health.qld.gov.au/bites-and-stings/insect-bites-and-stings">include</a>:</p>
<ul>
<li><p>gently washing the area with soap and water</p></li>
<li><p>using cold compresses on red and swollen stings. If you use an ice pack or ice, avoid direct contact with the skin</p></li>
<li><p>taking <a href="https://www.healthdirect.gov.au/antihistamines#:%7E:text=What%20are%20antihistamines%3F-,Antihistamines%20are%20medicines%20that%20you%20can%20take%20to%20treat%20allergies,called%20histamine%20in%20your%20body.">antihistamines</a>, which you can buy from your local pharmacy. </p></li>
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<p>Do not break the blisters that form at sting sites, and see your local doctor if the stings become more red and painful a few days later, to exclude infection.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bzzz-slap-how-to-treat-insect-bites-home-remedies-included-148722">Bzzz, slap! How to treat insect bites (home remedies included)</a>
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<h2>When to seek medical care</h2>
<p>Uncommonly, red imported fire ant stings can be <a href="https://pubmed.ncbi.nlm.nih.gov/2760357/">life threatening</a>. <a href="https://www.ncbi.nlm.nih.gov/books/NBK470576/">About 2%</a> of people who are stung develop a severe and life-threatening allergic reaction known as anaphylaxis. This has also been <a href="https://pubmed.ncbi.nlm.nih.gov/12064982/">reported</a> in Australia. </p>
<p><a href="https://www.allergy.org.au/patients/insect-allergy-bites-and-stings/allergic-reactions-to-bites-and-stings">Many stinging animals</a> in Australia can cause anaphylaxis, including bees, wasps, and other ants such as <a href="https://www.allergy.org.au/patients/insect-allergy-bites-and-stings/jack-jumper-ant-allergy">jack jumper ants</a>.</p>
<p>People allergic to some wasps may also <a href="https://pubmed.ncbi.nlm.nih.gov/26708389/">be allergic</a> to venom from the red fire ants. </p>
<p>Symptoms of anaphylaxis after being stung by a fire ant are similar to those after being stung by other animals. <a href="https://www.allergy.org.au/patients/about-allergy/anaphylaxis">Symptoms include</a>:</p>
<ul>
<li><p>difficulty talking or breathing</p></li>
<li><p>noisy breathing</p></li>
<li><p>swelling of the face (including lips, eyes or tongue)</p></li>
<li><p>tightness in the throat, with difficulty swallowing</p></li>
<li><p>dizziness</p></li>
<li><p>collapsing. </p></li>
</ul>
<p>There may also be a spreading red rash (hives or welts).</p>
<p>If you have any <a href="https://www.allergy.org.au/patients/about-allergy/anaphylaxis">of these symptoms</a>, seek immediate medical assistance. This may including calling 000. </p>
<p>Rarely, the ant venom can cause other toxic effects, which may be more likely in people who have been stung hundreds of times. So seek medical advice if you have unexplained or unusual symptoms after you’ve been stung.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ants-bees-and-wasps-the-venomous-australians-with-a-sting-in-their-tails-51024">Ants, bees and wasps: the venomous Australians with a sting in their tails</a>
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<h2>Avoid these ants if you can</h2>
<p>Avoid exposing yourself to imported red fire ants. Report nests to authorities. Do not handle the nests yourself as this is more likely to spread the ants. This is also when you’re most likely to be stung.</p>
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<p><em>If this article raises health concerns for you or for someone you know about insect stings call the <a href="https://www.poisonsinfo.nsw.gov.au">Poisons Information Centre</a> from anywhere in Australia on 131 126. This evidence-based advice is available 24 hours a day. For life-threatening symptoms, call 000.</em></p><img src="https://counter.theconversation.com/content/218908/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Darren Roberts is the Medical Director of the NSW Poisons Information Centre </span></em></p>Most stings can be safely handled at home. But in rare cases, you can get a serious allergic reaction, which needs urgent medical attention.Darren Roberts, Conjoint Associate Professor in clinical pharmacology and toxicology, St Vincent’s Healthcare Clinical Campus, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2125012023-09-19T14:47:51Z2023-09-19T14:47:51ZWhy invasive ants are a silent threat to our ecosystems<figure><img src="https://images.theconversation.com/files/548832/original/file-20230918-27-85srij.jpg?ixlib=rb-1.1.0&rect=0%2C13%2C3113%2C2316&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The yellow crazy ant (Anoplolepis gracilipes) is a notorious invasive ant species.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/yellow-crazy-ant-anoplolepis-gracilipes-1960533274">Lukman_M/Shutterstock</a></span></figcaption></figure><p>Invertebrates are often described by <a href="https://faculty.washington.edu/timbillo/Readings%20and%20documents/ABRIDGED%20READINGS%20for%20PERU/Wilson_1987_Little_things_that_run.pdf">experts</a> as the “little things that run the world”, and ants are certainly one of the top contenders for this role. Ants help ecosystems to function normally and the <a href="https://www.pnas.org/doi/full/10.1073/pnas.2201550119">total weight</a> of all ants on Earth is roughly equivalent to 1.4 billion people, or 33 Empire State Buildings. </p>
<p>Unfortunately, some ants have become invasive species – organisms transported to a new ecosystem that cause damage. These introductions typically happen accidentally by people but can have dire consequences, as my team’s <a href="https://resjournals.onlinelibrary.wiley.com/doi/10.1111/icad.12672">new research</a> shows. </p>
<p>Invasive species are thought to be the <a href="https://link.springer.com/article/10.1007/s10531-018-1595-x">second largest</a> threat to biodiversity after habitat destruction. They are a <a href="https://doi.org/10.1016/j.tree.2005.01.003">leading cause</a> of animal extinctions, potentially leading to species extinction and ecosystem failure. </p>
<p>The International Union for the Conservation of Nature includes <a href="https://portals.iucn.org/library/sites/library/files/documents/2000-126.pdf">five different ant species</a> on its list of 100 of the world’s worst invasive alien species. But while invasive ants have dramatically transformed some of the areas they have been able to invade, other areas appear to be far less affected, or even totally unaffected.</p>
<h2>How bad are invasive ants, really?</h2>
<p>My team’s <a href="https://resjournals.onlinelibrary.wiley.com/doi/10.1111/icad.12672">study</a> draws from research conducted around the world to provide a measure of how bad or good invasive ants are for biodiversity loss. The results show us that invasive ants are every bit as bad as we had assumed.</p>
<p>We extracted data from 46 different research articles that studied how animal communities reacted to invasive ants, and combined the results. We only selected research that was done in relatively “undisturbed” natural environments, free from intensive human activity. </p>
<p>These are areas that invasive ants have dispersed to from more degraded habitats or urban environments. This allows us to more confidently claim that any negative or positive effects on animal communities are because of invasive ants, rather than other invasive species or some form of human disturbance such as agriculture or deforestation.</p>
<p>Our results show that animal communities respond overwhelmingly negatively to invasive ants. We found there were on average 50% fewer individual animals and species in areas invaded by ants, which is a dramatic fall in biodiversity. It is also important to remember these results are averages and, therefore, invasive ants may spell doom for some animal communities above and beyond these numbers.</p>
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<img alt="A close up of an ant with a large head crawls along a mossy piece of bark." src="https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/548020/original/file-20230913-19-n2k3ar.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The <em>Pheidole megacephala</em> or big-headed ant.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/macro-image-bigheaded-ant-2215004569">Alen thien/Shutterstock</a></span>
</figcaption>
</figure>
<p>We also found that certain animal types, such as birds, reptiles and beetles, reacted more strongly than others. Native ants were the most strongly affected group. </p>
<p>This makes sense because many native ants will not only be directly attacked by invasive ants but they will also need to compete with them for food and nest sites. This is also bad news because of the general importance of native ants to the wider ecosystem. </p>
<p>Other groups that were badly affected were birds, beetles, butterflies, moths and reptiles. </p>
<p>We also found that the number of individuals in one insect group – bugs such as scale insects, aphids and mealybugs – increased. This group forms “mutualisms” with ants, which is where each species has a net benefit. </p>
<p>These insects are sap-sucking and exude a sugary liquid called “honeydew”, which ants love. Ants will defend these insects from their predators and parasites in return for this sugary secretion, enabling their populations to mutually increase. In some cases, these mutualisms can facilitate invasion – and to disastrous effect. </p>
<h2>How can something so small cause such a big problem?</h2>
<p>Although ants are small relative to how people perceive the world, they are numerous and tend to interact with a wide range of other organisms. This means they may be able to influence the ecosystem from multiple angles of attack. Invasive ants probably actively hunt down other species but competition for food or space is also important. </p>
<p>Ultimately, we need more research that can tease apart how ants are interacting with other species when they invade a location. What do they eat? Who do they compete with for food? Which habitats do they prefer and why? These questions urgently need answers so we can understand, prioritise and optimise how to minimise the negative effects of invasive ants.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/why-red-fire-ants-and-yellow-crazy-ants-have-given-themselves-a-green-light-to-invade-australia-208479">Why red fire ants and yellow crazy ants have given themselves a green light to invade Australia</a>
</strong>
</em>
</p>
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<p>Overall, our research is worrying. The reduction in animal diversity may have severe consequences for ecosystem functioning and the long-term future of rare species. Although there are crucial considerations to mitigate or reverse these effects, the conservation implications are not straightforward. </p>
<p>Ant eradication regimes are logistically complex and financially expensive, for example, and more than half <a href="https://doi.org/10.1016/j.biocon.2016.03.036">fail</a>. Early detection technology, as well as control measures such as toxic baits, can help conservationists prevent or reverse the effects of invasive ants on our ecosystems.</p>
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<figure class="align-right ">
<img alt="Imagine weekly climate newsletter" src="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434988/original/file-20211201-21-13avx6y.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p class="fine-print"><em><span>Maximillian Tercel receives funding from Natural Environment Research Council and Durrell Wildlife Conservation Trust.</span></em></p>Invasive ants are a major threat to biodiversity, according to a study.Maximillian Tercel, PhD Candidate in Entomology, Cardiff UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2111272023-08-28T20:03:56Z2023-08-28T20:03:56ZA battlefield for ants? New study on ant warfare shows we could manipulate their fights<figure><img src="https://images.theconversation.com/files/542462/original/file-20230813-108238-w4bkeb.jpg?ixlib=rb-1.1.0&rect=0%2C903%2C3234%2C1887&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Bruce Webber</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Humans are not the only animals <a href="https://doi.org/10.1080/10407413.2020.1846456">that go to war</a>. Ants do so too, and on a similarly catastrophic scale.</p>
<p>Battles play out daily – in human conflicts, among animals in nature, and across the virtual worlds of video games. How these battles progress depends on the combatants involved and what their battlefields are like.</p>
<p>In a new study <a href="http://dx.doi.org/10.1073/pnas.2217973120">published in PNAS today</a>, we used mathematical models on video game simulations to test how battlefield dynamics change warfare outcomes. We then confirmed these concepts in the real world – using ant battles.</p>
<h2>The mathematics of a battle</h2>
<p>Despite the horror of war, it occupies a prominent place in public imagination. In the early 1900s, English engineer Frederick William Lanchester developed a mathematical model that described the outcome of battles as dependent on the individual strength of each soldier in opposing armies, and on the size of each army. </p>
<p>To this day, <a href="https://www.tandfonline.com/doi/full/10.1080/10407413.2020.1846456">Lanchester’s laws</a> remain valuable tools for evaluating battles. Investing in a few strong soldiers should be more effective when battles resemble a series of one-on-one duels. On the other hand, investing in large armies should be more effective when they can surround their enemies and concentrate their attacks.</p>
<p><a href="https://doi.org/10.1093/beheco/11.6.686">Later research</a> by evolutionary biologists Nigel Franks and Lucas Partridge revealed it’s not just the soldiers. The complexity of the battlefield itself can also tip the balance in favour of one strategy over another.</p>
<p>When fighting in tunnels, alleyways, or difficult terrain, it’s harder for large armies to surround their opponents, so small forces of strong or savvy soldiers can succeed. Such tactics are the basis for the story of Spartans holding off hundreds of thousands of Persian soldiers at the <a href="https://www.nationalgeographic.co.uk/history-and-civilisation/2022/01/betrayal-crushed-spartas-last-stand-at-the-battle-of-thermopylae">Battle of Thermopylae</a> in 480 BCE.</p>
<h2>Age of Empires II versus ants</h2>
<p>In our study, we first used the video game <a href="https://www.ageofempires.com/">Age of Empires II</a> to assess the importance of battlefield complexity.</p>
<p>This game allows players to arrange different soldier types, build maps and fight against computer-driven enemies. In featureless battlefields, small armies of strong infantry units (Teutonic Knights) could defeat up to 50 weaker units (Two-Handed Swordsmen), but no more.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="In a video game, a group of nine soldiers in blue are surrounded by a larger group of soldiers in red" src="https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=292&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=292&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=292&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=367&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=367&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542468/original/file-20230813-101760-mirg3t.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=367&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A small army of Teutonic Knights (blue) are surrounded and overwhelmed by 60 Two-Handed Swordsmen in a simple battlefield in the strategy game, Age of Empires II.</span>
<span class="attribution"><span class="source">Age of Empires II</span></span>
</figcaption>
</figure>
<p>However, in complex battlefields, nine Knights could slay up to 70 Swordsmen. We found that video game wars, even though not explicitly programmed to do so, clearly followed Lanchester’s laws. But how relevant are these laws to real-world battles?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="In a video game, groups of soldiers in red move down narrow alleyways of land between strips of water. Facing them in the alleyways are small groups of soldiers in blue" src="https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=291&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=291&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=291&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=365&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=365&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542469/original/file-20230813-196116-xbiy6a.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=365&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In a complex battlefield, the same army of Swordsmen are unable to surround the Knights, and are instead funnelled between barriers of water. Now, the Knights have fewer Swordsmen to face at any one time.</span>
<span class="attribution"><span class="source">Age of Empires II</span></span>
</figcaption>
</figure>
<p>Most animals do not engage in warfare on the same scale as humans. This is because there’s no evolutionary incentive in risking their lives for a cause in which they don’t necessarily have a direct stake.</p>
<p>Social insects such as ants <a href="https://doi.org/10.1080/10407413.2020.1846456">are an exception</a>, because through warfare, the evolutionary future of the sterile worker ants who do the fighting is invested in the greater good of the colony.</p>
<p>Testing Lanchester’s laws required two ant species that clearly differed in their fighting prowess. Our first combatant was the Australian meat ant, <em>Iridomyrmex purpureus</em>. These large and beautiful ants, with their conspicuous gravelly nests, are familiar to many people in regional Australia as they are dominant in undisturbed or remnant bushland habitats.</p>
<p>As their enemies, we selected the notorious Argentine ant, <em>Linepithema humile</em>. These aggressive invasive ants are comparatively tiny but live in <a href="https://doi.org/10.1016/j.tree.2009.01.013">extremely large, hyper-cooperative colonies</a>.</p>
<p>Because of the size difference, meat ants always defeat Argentine ants in one-on-one duels. We formed small armies of 20 meat ants, and opposed them in the lab to increasingly large armies of up to 200 Argentine ants.</p>
<p>These battles took place either in simple arenas (featureless plastic containers) or complex arenas (the same containers with narrow wooden strips glued to the floor).</p>
<p>As predicted by Lanchester’s laws and by our video gaming, fewer large meat ants died in battle in complex arenas compared to simple ones.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large ant is being attacked by two smaller ants, while another large ant stands to the side" src="https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=420&fit=crop&dpr=1 600w, https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=420&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=420&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=528&fit=crop&dpr=1 754w, https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=528&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/542467/original/file-20230813-29-sz0e9o.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=528&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A meat ant grapples with two smaller Argentine ant adversaries, while a fellow meat ant watches on.</span>
<span class="attribution"><span class="source">Bruce Webber</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Understanding ant invasions</h2>
<p>Experiments like this can inform us about the dynamics between native and non-native invasive ants. <a href="https://theconversation.com/why-red-fire-ants-and-yellow-crazy-ants-have-given-themselves-a-green-light-to-invade-australia-208479">Non-native invasive ants</a> are some of the worst pests on the planet, costing the global economy <a href="https://doi.org/10.1007/s10530-022-02791-w">tens of billions of dollars per year</a>. Ecosystem managers are keenly interested in new ways to manipulate the competitive success of these invaders.</p>
<p>One of the unifying features of non-native invasive ants is that, like our Argentine ants, they are generally individually <a href="https://doi.org/10.1086/303270">smaller than non-invasive species</a> in the areas they invade, while living in extremely large colonies. It has also been observed that non-native invasives are <a href="https://doi.org/10.1603/0013-8746(2004)097%5b0513:COFCFN%5d2.0.CO;2">particularly dominant in disturbed environments</a>. </p>
<p>While there are many possible reasons for this, disturbed environments are often simplified at ground level, with the removal of undergrowth and natural debris creating open battlefields.</p>
<p>The fact that small but numerous non-native invasive ants are more successful against their large native competitors in simplified environments makes sense, in light of our experimental study of ant warfare.</p>
<p>It also suggests that adding ground-level complexity, such as natural debris, may tip the balance in favour of larger native species. Just like for humans (and in computer games), the outcome of ant wars depends on the nature of the battlefield.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-know-if-were-winning-the-war-on-australias-fire-ant-invasion-and-what-to-do-if-we-arent-121367">How to know if we’re winning the war on Australia’s fire ant invasion, and what to do if we aren't</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/211127/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Samuel Lymbery was supported by a Forrest Prospect Fellowship from the Forrest Research Foundation.</span></em></p><p class="fine-print"><em><span>Bruce Webber is supported by CSIRO Health & Biosecurity. </span></em></p><p class="fine-print"><em><span>Raphael Didham does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Mathematical models, video games and experiments with ants can all further our understanding of the dynamics of war.Samuel Lymbery, Postdoctoral Fellow in Biosecurity, Murdoch UniversityBruce Webber, Principal Research Scientist, CSIRORaphael Didham, Professor of Ecology, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2092712023-07-26T11:09:48Z2023-07-26T11:09:48ZAustralian ant honey inhibits tough pathogens, new research shows<figure><img src="https://images.theconversation.com/files/539207/original/file-20230725-19-ukl2g.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4031%2C3024&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Danny Ulrich and Andrew Dong</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The medicinal value and potent antimicrobial activity of <a href="https://theconversation.com/science-or-snake-oil-is-manuka-honey-really-a-superfood-for-treating-colds-allergies-and-infections-78400">honey</a> has been a topic of considerable interest in recent years, particularly in light of the alarming rise in antibiotic resistance. </p>
<p>While most honey comes from honey bees (<em>Apis mellifera</em>), <a href="https://theconversation.com/wasps-aphids-and-ants-the-other-honey-makers-102838">other insects</a> such as stingless bees, wasps and even ants can produce honey-like products from plant nectar. </p>
<p>One of these insects is the honeypot ant <em>Camponotus inflatus</em>, found throughout the central desert region of Australia. We set out to determine whether its honey might be medically useful.</p>
<p>Our results, <a href="https://doi.org/10.7717/peerj.15645">published in PeerJ</a>, show the honey has powerful anti-microbial effects, particularly against certain heat-tolerant yeasts and moulds which resist most current antifungal drugs.</p>
<h2>Pots of gold</h2>
<p>Honeypot ants are social ant species that develop large nests in the soil. Within these colonies, certain worker ants known as “repletes” serve as living food stores. </p>
<p>The repletes are fed by other members of the colony, who forage for nectar and honeydew in the environment. The repletes accumulate a golden honey-like substance in their flexible abdomens. </p>
<p>The repletes become so engorged with honey they are rendered almost immobile. They hang together from the ceiling of the nest, forming a sort of ant pantry. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539249/original/file-20230725-25-6avf8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Honeypot ant ‘repletes’ store honey for the nest.</span>
<span class="attribution"><span class="source">Andrew Dong</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In times of need, other worker ants visit the repletes and stroke their antennae. The repletes cough up some honey in response, and the other workers then distribute it throughout the colony.</p>
<p>Most honeypot ants live in very dry environments. Their unusual lifestyle has been so successful it has <a href="https://www.tandfonline.com/doi/abs/10.1080/03949370.1991.10721919">evolved multiple times</a>.</p>
<h2>Honeypot ants in First Nations culture</h2>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=645&fit=crop&dpr=1 600w, https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=645&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=645&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=811&fit=crop&dpr=1 754w, https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=811&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/539244/original/file-20230725-28-emh9ho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=811&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Digging for honeypot ants.</span>
<span class="attribution"><span class="source">Danny Ulrich</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In Australia, <em>Camponotus inflatus</em> is found throughout the central desert region and holds cultural and nutritional significance to local Indigenous people. </p>
<p>Danny Ulrich of the Tjupan language group, operator of <a href="https://goldfieldshoneyanttours.com.au/">Goldfields Honey Ant Tours</a> in Kalgoorlie, Western Australia, says</p>
<blockquote>
<p>For our people, honey ants are more than just a food source. Digging for them is a very enjoyable way of life. It’s a way of bringing the family together, to connect with each other and nature. </p>
</blockquote>
<p>There are also reports of traditional use of honeypot ant honey for treating ailments like colds and sore throats, and possibly as a topical ointment to help keep infections at bay, suggesting potential antimicrobial properties.</p>
<h2>Not your usual honey activity</h2>
<p>To investigate further, we obtained honeypot ant repletes from Goldfields Honey Ant Tours, collected and pooled the honey from the ants and tested its ability to inhibit various pathogenic bacteria, yeasts and moulds. </p>
<p>We compared this to two well-studied bee honeys with anti-microbial properties: manuka honey from New Zealand, and jarrah honey from Western Australia. </p>
<p>Our <a href="https://doi.org/10.7717/peerj.15645">results</a> revealed striking differences between the honeypot ant honey and the bee honeys. </p>
<p>Both bee honeys showed broad activity and were able to inhibit every pathogen tested at similar levels. However, the honeypot ant honey showed remarkable potency against certain microbes, but little against others.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/science-or-snake-oil-is-manuka-honey-really-a-superfood-for-treating-colds-allergies-and-infections-78400">Science or Snake Oil: is manuka honey really a 'superfood' for treating colds, allergies and infections?</a>
</strong>
</em>
</p>
<hr>
<p>Important factors that contribute to the <a href="https://www.sciencedirect.com/science/article/abs/pii/S0023643820313682">antimicrobial power</a> of bee honey are its high sugar and low water content, which sucks the water out of microbial invaders.</p>
<p>We found honeypot ant honey to have a much higher moisture content than the bee honeys, however, putting it in a range that could support the growth of some microorganisms. </p>
<p>Most bee honeys also contain enzymes that produce hydrogen peroxide, a known antimicrobial compound. However, honeypot ant honey retained most of its activity even after we removed all the hydrogen peroxide. </p>
<p>Finally, some honeys contain antimicrobial proteins and peptides that are derived from the honey bee. These can be destroyed by heat, and when we heated the honeypot ant honey to 90°C for 10 minutes it lost most of its antimicrobial activity. </p>
<p>We therefore think this unique antimicrobial activity is likely due to proteins or peptides, and these are probably derived from the honeypot ant.</p>
<h2>Evolution of antimicrobial activity in the insect world</h2>
<p>In the natural environment, animals, plants, and the products they make are exposed to a huge range of microorganisms looking for their next meal. Sweet, nutritious honey is an enticing food source for these microbial scavengers and must be vigorously protected, both to prevent its spoilage and to stop invasion of the hive or nest by rapidly growing moulds. </p>
<p>Intriguingly, we found honeypot ant honey was particularly effective against some pathogens we consider to be quite “tough”. These pathogens are well adapted to living in soils and dry conditions, and can also cause very serious infections in people with severely weakened immune systems. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/wasps-aphids-and-ants-the-other-honey-makers-102838">Wasps, aphids and ants: the other honey makers</a>
</strong>
</em>
</p>
<hr>
<p>In particular, the ant honey was able to inhibit heat-tolerant yeasts and moulds that are likely to be present in the honey ant nest and surrounding environment. Importantly, these can be very difficult to kill with most currently available <a href="https://www.mdpi.com/2218-1989/10/3/106">antifungal drugs</a>.</p>
<p>We suggest the evolutionary pressure imposed by these soil microorganisms has resulted in the potent, selective antimicrobial activity of honeypot ant honey.</p>
<h2>Science catches up with Indigenous knowledge</h2>
<p>Our results clearly support the medicinal use of honeypot ant honey by Australian Indigenous communities and provide a new understanding of the intricate relationship between honeypot ants, their environment, and the remarkable antimicrobial activity exhibited by their honey. </p>
<p>Due to the cultural significance of the ants, and challenges with rearing them at a commercial scale, it is not feasible to domesticate honeypot ants for honey production. </p>
<p>However, honeypot ant honey may provide valuable insights for the development of useful new antimicrobial peptides. These may help expand our arsenal of effective antibacterial and antifungal treatments, which are increasingly needed to combat emerging challenges in healthcare.</p><img src="https://counter.theconversation.com/content/209271/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dee Carter has received funding to support work on honey bee honey from The Rural Industries Research and Development Corporation, AgriFutures, the Australian Research Council (Linkage program), and the NSW Government under the Bushfire Industry Recovery Package.</span></em></p><p class="fine-print"><em><span>Danny Ulrich is the operator of Goldfields Honey Ant Tours.</span></em></p><p class="fine-print"><em><span>Kenya Fernandes conducts research on honey bees and medicinal honey supported by the NSW Government under the Bushfire Industry Recovery Package.</span></em></p><p class="fine-print"><em><span>Nural Cokcetin has received funding to support research on honey bees and medicinal honey from AgriFutures Australia and the NSW Government under the Bushfire Industry Recovery Package. She is a member of the NSW Apiarists' Association. </span></em></p><p class="fine-print"><em><span>Andrew Dong does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Experiments show honey from Australian desert ants has potent antimicrobial power.Dee Carter, Professor of Microbiology, University of SydneyAndrew Dong, Research Affiliate, Microbiology, University of SydneyDanny Ulrich, Operator, Goldfields Honey Ant Tours, Indigenous KnowledgeKenya Fernandes, Postdoctoral Researcher, University of SydneyNural Cokcetin, Research scientist, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2093272023-07-10T20:10:53Z2023-07-10T20:10:53ZHumans set budgets when facing an uncertain future. So do ants <figure><img src="https://images.theconversation.com/files/536396/original/file-20230709-173516-ajhf4y.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4261%2C3450&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Simon Garnier</span></span></figcaption></figure><p>Imagine you are looking for a parking spot at a crowded event. You find one far from your destination. Do you decide to take it, or invest more time into hunting a better spot which may or may not exist?</p>
<p>You might resolve this decision by “budgeting”: limiting the resources (time) you will spend looking for a better option before settling for the inferior one. This strategy, which allows us to cut our losses when things don’t pan out as we had hoped, is commonly used when we cannot know the payoff of our choices in advance.</p>
<p>Making decisions under uncertainty is a problem we all face. In <a href="https://www.pnas.org/cgi/doi/10.1073/pnas.2216217120">new research</a> published in the Proceedings of the National Academy of Sciences, we show weaver ants (<em>Oecophylla smaragdina</em>) – much like humans – manage it by budgeting their investment into a task with an uncertain payoff. </p>
<h2>Weaver ants bridge gaps with their own bodies</h2>
<p>Weaver ants link their bodies together to form bridge-like structures called “hanging chains”, which they use for crossing gaps encountered along trails. Chains span several times the size of an individual ant and, most strikingly, are self-organized. </p>
<p>This means chains are formed without the help of leaders or external blueprints. Instead, each individual responds solely to its surroundings and local interactions with neighbours. </p>
<p>Understanding self-organization is central to understanding collective behaviour in animal groups – from flocks of birds to insect swarms – and other systems, including human crowds and traffic flow. </p>
<h2>Chains are a gamble</h2>
<p>Building a chain comes at a cost to the colony. Ants in the chain can’t participate in important colony tasks such as defending the nest and foraging. The cost of the chain is proportional to its length: longer chains are more costly, as they keep more ants occupied. </p>
<p>Chains provide a major benefit too: they allow ants to explore areas that would otherwise be inaccessible, which may offer food sources to the colony. Whether an area contains a profitable resource, however, is unknown to the ants until the chain has been completed. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three photos showing a chain of ants slowly growing downward from one platform to another." src="https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=402&fit=crop&dpr=1 754w, https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=402&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/536390/original/file-20230709-21-b82382.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=402&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A chain grows as new ants arrive and join the collective attempt to reach the ground below.</span>
<span class="attribution"><span class="source">Daniele Carlesso</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>This makes chain-building a gamble. Colonies must invest capital (a number of ants) into forming a chain, which may or may not pay off. </p>
<p>In our study we asked whether, like humans, ants budget their investment into a task when the payoffs are unknown. We expected ants would stop forming chains when the gap to be bridged became too tall, as the cost of the chain would become too great. </p>
<h2>A simple mechanism for a complex decision</h2>
<p>We initially challenged ants to bridge vertical gaps of 25mm, 35mm and 50mm in height. Ants could comfortably form chains within this range, which allowed us to precisely determine the rules they use to build chains. </p>
<p>A detailed analysis of the ants’ behaviour revealed that joining and leaving events happen primarily in the lowest part (1cm) of chains. This indicates that ants are unable to leave their position if one or more individuals start hanging from them. </p>
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<strong>
Read more:
<a href="https://theconversation.com/bridges-highways-scaffolds-how-the-amazing-engineering-of-army-ants-can-teach-us-to-build-better-158326">Bridges, highways, scaffolds: how the amazing engineering of army ants can teach us to build better</a>
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<p>We then found ants decide how long to stay in a chain by visually assessing their distance from the ground below. The closer to the ground, the longer an ant remains in the chain. </p>
<p>Chain formation is thus modulated by a simple rule: each ant remains in the chain for a length of time proportional to her distance to the ground, and remains stuck in place if one or more ants start hanging from her. The ant will then be able to move only if the other ant(s) leave. </p>
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<figcaption><span class="caption">Ants bridging a 50mm gap. Daniele Carlesso.</span></figcaption>
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<p>Can this rule predict a distance beyond which ants stop forming chains? We answered this question using a mathematical model, which predicted ants should stop forming chains when the gap is taller than 89mm.</p>
<p>To confirm these predictions, we asked ants to form chains over gaps of 110mm – a distance well beyond the threshold predicted by our model. As expected, ants never formed chains over these gaps. </p>
<h2>Tricking ants into investing more</h2>
<p>If ants use vision to assess their distance from the ground, we should be able to trick them into building very long chains (greater than 90mm) by keeping the ground at a constant distance from the bottom of the chain. </p>
<p>We ran an additional experiment where we could lower the platform ants had to reach using a slider. As the chain grew, we lowered the platform, keeping it just out of reach of the ants. Using this apparatus, we tricked ants into forming chains as long as 125mm. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bees-are-astonishingly-good-at-making-decisions-and-our-computer-model-explains-how-thats-possible-208189">Bees are astonishingly good at making decisions – and our computer model explains how that's possible</a>
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<p>Similar to when we set ourselves a time limit for finding parking, ants set a distance limit before giving up. And they do so using a simple rule – remain in the chain for a length of time proportional to your distance to the ground. </p>
<p>Our results reveal how simple rules can guide groups in making adaptive collective decisions in the absence of payoff information. Not only does this help us understand ants – it also provides an algorithm for decision-making in uncertain scenarios, which can be applied in multi-agent artificial systems such as swarm robotics.</p><img src="https://counter.theconversation.com/content/209327/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniele Carlesso receives funding from Macquarie University.</span></em></p>Weaver ants organise themselves into bridges to cross gaps and explore new territory – and new research shows this collective behaviour is governed by a surprisingly simple decision-making rule.Daniele Carlesso, PhD Candidate, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2084792023-06-29T02:43:35Z2023-06-29T02:43:35ZWhy red fire ants and yellow crazy ants have given themselves a green light to invade Australia<p>Two of the worst ant pests on the planet are invading Australia. <a href="https://www.outbreak.gov.au/current-outbreaks/red-imported-fire-ant">Red imported fire ants</a> have been detected for the first time on the western side of the Great Dividing Range <a href="https://www.abc.net.au/news/2023-06-13/red-fire-ants-detected-in-toowoomba/102471816">in Toowoomba</a>, Queensland. <a href="https://www.csiro.au/en/research/animals/pests/yellow-crazy-ants">Yellow crazy ants</a> recently reached <a href="https://www.abc.net.au/news/rural/2023-06-11/another-crazy-yellow-ant-infestation-confirmed-in-whitsundays/102455994">the Whitsundays</a>.</p>
<p>The yellow crazy ant (<em>Anoplolepis gracilipes</em>) ranks among the world’s <a href="http://www.iucngisd.org/gisd/100_worst.php">100 worst animal pests</a> because of its impacts on <a href="https://www.csiro.au/en/research/animals/pests/yellow-crazy-ants">agriculture and biodiversity</a>. The red imported fire ant (<em>Solenopsis invicta</em>) poses <a href="https://www.fireants.org.au/dangers/impacts">similar threats</a>, and is also one of the world’s most dangerous ants. Its intensely painful stings, which give the ant its name, <a href="https://www.fireants.org.au/dangers/impacts/health-impacts">can kill people</a>.</p>
<p>The prospects of total eradication of these ants in Australia are poor. Both species are highly adaptable and colonies need to be detected and eradicated early to contain them. Eradication efforts face other several challenges, including:</p>
<ul>
<li><a href="https://www.abc.net.au/news/rural/2021-06-08/australia-biosecurity-slammed-in-auditor-general-report/100179624">inadequate biosecurity resources</a> for checking incoming cargo</li>
<li>the need for the public to maintain constant vigilance</li>
<li>spread from built-up urban areas into bushland that’s much harder to monitor</li>
<li>other pressing issues, such as the housing crisis, demand attention and resources, crowding out threats from insects. </li>
</ul>
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<figcaption><span class="caption">Red imported fire ants are a threat to people, biodiversity and agriculture.</span></figcaption>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/eradicating-fire-ants-is-still-possible-but-we-have-to-choose-now-70199">Eradicating fire ants is still possible, but we have to choose now</a>
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</em>
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<hr>
<h2>Where did the crazy ants come from?</h2>
<p>The origin of yellow crazy ants is disputed but is likely in South-East Asia or Africa. Workers are yellowish orange, medium-sized (around 4-5mm) and have long legs and antennae. They run rapidly in a seemingly random fashion, hence their name.</p>
<p>Workers and queens have a small funnel on their gasters (the bulbous end of their bodies) from which they can spray formic acid. It can burn human skin and is lethal for other ants and many native arthropods. Small animals such as lizards and bird chicks are at risk of being blinded or eaten.</p>
<p>These ants have spread to much of South-East Asia, parts of central America and the United States. They can be found indoors in the United Kingdom and a handful of European nations. </p>
<p>Since reaching the Australian territory of Christmas Island, yellow crazy ants have devastated the native wildlife. They killed <a href="https://www.csiro.au/en/research/animals/pests/yellow-crazy-ants">up to 20 million</a> of the famous red land crabs, causing major changes in the rainforest. </p>
<p>On the mainland, this species has reached the Northern Territory and Queensland, where it is most entrenched, having been discovered in Cairns in 2001. As well as spreading to Hervey Bay, Townsville and other coastal sites, the ant is now in Brisbane.</p>
<p>Brisbane City launched an <a href="https://www.abc.net.au/news/2022-09-12/yellow-crazy-ant-risk-low-to-high-brisbane-city-council/101396552">eradication plan</a> in 2022. Control measures include baiting using a fishmeal-based ant attractant combined with an insecticide. However, recently reported infestations in the Whitsundays and elsewhere suggest eradication will be difficult.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ant-invasion-how-pets-become-pests-157661">Ant invasion: How pets become pests</a>
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<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1569499517933998080"}"></div></p>
<p>Northern Territory authorities have had more success. Some <a href="https://www.csiro.au/en/research/animals/pests/yellow-crazy-ants">26 locations</a> covering nearly 300 hectares of Indigenous land have been freed of the pest.</p>
<p>The prospects of total eradication of yellow crazy ants in Australia are not promising. Like other serious ant pests, this species can form “super-colonies” with multiple queens, eats a wide variety of foods and readily colonises both exotic and native environments. </p>
<p>Such species are often only eradicated if their presence is detected before they become established. For eradication programs to succeed, local councils need landholders’ full support, plus adequate federal and state funding. Late last year the federal government <a href="https://minister.dcceew.gov.au/node/2511">provided another A$24.8 million</a>, so there is some hope.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/invasive-ants-federal-budget-takes-aim-but-will-it-be-a-lethal-shot-114818">Invasive ants: federal budget takes aim but will it be a lethal shot?</a>
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<h2>And what about the fire ants?</h2>
<p>The red imported fire ant differs from the yellow crazy ant in having two waist segments (instead of one) and a powerful sting. The workers vary in size between 2.5mm and 6mm. They are reddish or yellowish with a darker gaster. </p>
<p>The fire ants are less distinctive than the crazy ants. They look like some small native ants in the genera <em>Monomorium</em> and <em>Chelaner</em>. However, their <a href="https://ipm.ucanr.edu/TOOLS/ANTKEY/countanten.html">antennal clubs</a> have two segments, while these native ants have three segments. </p>
<p>Another introduced <em>Solenopsis</em> species, <em>S. geminata</em>, looks even more similar. They are distinguished by the teeth on the mandible, or jaws: the red imported fire ant has four teeth and the other species has three. The nest mound of <em>S. invicta</em> is distinctive without any obvious nest entrance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="The red earth nest mound of red imported fire ants" src="https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=448&fit=crop&dpr=1 600w, https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=448&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=448&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=563&fit=crop&dpr=1 754w, https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=563&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/534722/original/file-20230629-21-jbymfg.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=563&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A red imported fire ant nest mound features no obvious entrance hole.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/131104726@N02/16371103174/">Alex Wild/University of Texas</a></span>
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<p>Native to South America, red imported fire ants have spread to the southern US, the South American tropics, the Caribbean, China and some Pacific Islands. Indoor infestations have been reported in Finland and Canada. </p>
<p>In Australia this species has become established in south-east Queensland. Small incursions have been <a href="https://www.outbreak.gov.au/current-outbreaks/red-imported-fire-ant">eradicated</a> in Port Botany, New South Wales, and, more recently, Fremantle, Western Australia. </p>
<p>In the US, fire ant stings have caused <a href="https://pubmed.ncbi.nlm.nih.gov/2760357/">scores of human deaths</a> due to anaphylaxis, or allergic shock. The stings cause small pustules on the skin, which can lead to infection or tissue death.</p>
<p>Fire ant stings also kill or injure domestic animals and livestock, and can cause serious economic loss. Like the yellow crazy ant, this species will <a href="https://www.dcceew.gov.au/environment/invasive-species/insects-and-other-invertebrates/tramp-ants/red-imported-fire">protect disease-carrying plant bugs</a> that produce <a href="https://www.discoverwildlife.com/animal-facts/insects-invertebrates/honeydew/">honeydew</a>. The ants will attack anything that threatens their food source and so help the bug population grow. </p>
<p>The ants also <a href="https://www.agriculture.gov.au/sites/default/files/documents/Strategic%20Review%20of%20the%20National%20Red%20Imported%20Fire%20Ant%20Eradication%20Program%20August%202021.pdf">damage many crops</a> themselves and destroy honey bees in their hives. They may nest in electrical utility boxes, <a href="https://www.agriculture.gov.au/sites/default/files/documents/Strategic%20Review%20of%20the%20National%20Red%20Imported%20Fire%20Ant%20Eradication%20Program%20August%202021.pdf">causing outages</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/cannibalism-helps-fire-ants-invade-new-territory-113752">Cannibalism helps fire ants invade new territory</a>
</strong>
</em>
</p>
<hr>
<p>Spreading corn bait laced with insecticide is the main means of control. Insecticide or steam can also be injected into nests.</p>
<p>Unfortunately, red imported fire ants were only identified in Brisbane in 2001, some years after the estimated date of the first arrivals. These ants likely came from the US. Despite successful <a href="https://www.outbreak.gov.au/current-outbreaks/red-imported-fire-ant">eradications</a> at sites including the Port of Brisbane and a separate incursion in central Queensland, the Brisbane outbreak has not been controlled. </p>
<p>The prognosis for controlling this pest is grim. It has super-colonies like the crazy ant and is equally adaptable in terms of food, nest sites and multiple queens (in some, but not all colonies). On top of that, identification and detection are more difficult.</p><img src="https://counter.theconversation.com/content/208479/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brian Heterick does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The two pest ant species have huge impacts on the areas they invade. The fire ants can even kill people. Unfortunately, these ants will be hard to eliminate.Brian Heterick, Adjunct Research Associate, School of Molecular and Life Sciences, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2034502023-04-19T11:22:04Z2023-04-19T11:22:04ZHumans weren’t the first engineers, doctors and farmers – bacteria, plants and animals have lots to teach us<figure><img src="https://images.theconversation.com/files/521613/original/file-20230418-22-hx9xij.jpg?ixlib=rb-1.1.0&rect=23%2C0%2C5134%2C2992&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">There are hidden worlds in nature</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/water-gives-life-closeup-shot-droplet-2136956871">PeopleImages.com/Yuri A/Shutterstock</a></span></figcaption></figure><p>Life existed without human beings for more than 99.9% of Earth’s history. Yet we often ignore the achievements of species that preceded us by billions of years. </p>
<p>I explore the concept of nonhuman civilisations in my new book, <a href="https://www.chelseagreen.com/product/biocivilisations/">Biocivilisations</a>, which retells the story of life acknowledging the contributions of other species. Bacteria, plants, fungi, insects, birds, whales and other species demonstrate language, engineering, science, medicine, agriculture and more. These are all elements of civilisation that we associate with humans.</p>
<h2>Speaking nature’s language</h2>
<p>Whales communicate with each other using a series of sound clicks called codas. Sperm whales seem to <a href="https://asa.scitation.org/doi/10.1121/1.4949478">announce themselves</a> using a <a href="https://risweb.st-andrews.ac.uk/portal/en/researchoutput/individual-vocal-production-in-a-sperm-whale-physeter-macrocephalus-social-unit(e754bbe3-9305-4b57-85ba-545f224cf354).html">unique click sequence</a>, or name. By pooling their acoustic datasets, an international team of 27 researchers studying Pacific Ocean sperm whales identified <a href="https://www.pnas.org/doi/full/10.1073/pnas.2201692119">seven sperm whale vocal clans</a>, each with their own dialect and identity codas. Now, scientists from around the world are collaborating as part of the <a href="https://www.projectceti.org/">Cetacean Translation Initiative</a> to use powerful AI algorithms and decode the language of sperm whales. </p>
<p>Plants <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/pce.13910">communicate with each other using hormones</a> such as <a href="https://bmcbiol.biomedcentral.com/articles/10.1186/s12915-016-0308-8">jasmonate</a>, which redirects resources from growth to repairing damage. They release hormones into the air when in distress, such as when insects attack them. Neighbouring plants then pick up on the signal and respond by preparing for attacks – for example, by releasing toxins to ward off the insects.</p>
<p>Meanwhile, bacteria have been <a href="https://www.annualreviews.org/doi/10.1146/annurev.cellbio.21.012704.131001">“talking” to each other </a>for billions of years by exchanging chemical messages via hormone-like molecules called autoinducers. They use these chemicals to synchronise action. For example, bacteria may only invade a cell if enough neighbouring bacteria are releasing autoinducers. This is called <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1002953">quorum sensing</a>. </p>
<p>Bacteria also communicate with the cells of other species, including ours. Recent research showed certain chemicals that bacteria release influence the development of our brains, <a href="https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(21)00380-2?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1931312821003802%3Fshowall%3Dtrue">allowing the brain tissue to mature properly</a>. Studies into premature babies have shown the relationship between gut bacteria and human cells are crucial for cognitive development. </p>
<h2>Skilled engineers</h2>
<p>Our planet also reverberates with construction noise. It is a permanent building site where bacteria, insects and humans alike create cities. </p>
<p>The engineering skills of honeybees are so sophisticated that a honeybee expert and a group of engineers used <a href="https://www.youtube.com/watch?v=elTfueXcYaU">an algorithm inspired by honeybees</a> to resolve internet traffic problems. They copied the process bees use to distribute foragers searching a floral field for nectar. </p>
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<p>Bacteria are skilled engineers too. In one study, scientists used powerful microscopes and time-lapse imaging to record the <a href="https://www.nature.com/articles/s41467-020-15165-4">city-building skills</a> of a bacterial species that lives in human mouths, <em>Streptococcus mutans</em>. Bacteria produce their own building materials when they settle at a new site, normally a hard surface. These materials include carbohydrates, proteins and even DNA secreted by their tiny bodies. The building material is carefully distributed so that the village structure acquires a three-dimensional shape. </p>
<p>Some of these bacteria-settlers remain stationary and meld themselves to the surface that the village is built on, enhancing its structural stability. Bacteria can also move within villages and divide their bodies to increase the population. Villages grow, join together and form bacterial cities and megacities – much like modern London is a <a href="https://www.mattbarrett-travel.com/london/london-villages/index.htm">collection of former villages and towns</a>.</p>
<p>The communication between bacterial megacities is <a href="https://www.nature.com/articles/nature15709">conducted through electrical impulses</a>. Indeed, the entire planet was turned into a kind of <a href="https://theconversation.com/microbes-have-their-own-version-of-the-internet-75642">bacterial internet</a> three billion years ago.</p>
<h2>Doctors and surgeons</h2>
<p>Arguably, bacteria were also the first practitioners of medicine. Viruses invade bacteria and hijack their cellular machinery to make copies of themselves – a process which kills the bacteria. So, three billion years ago, bacteria became “epidemiologists” to defend themselves. </p>
<p>Bacterial bodies produce enzymes <a href="https://www.nature.com/articles/s41579-019-0278-2">that attack and kill virus DNA</a>, a technique known as <a href="https://pubmed.ncbi.nlm.nih.gov/26771483/">Crspr</a>. It can target a section of DNA, bind to it and turn the gene off. Scientists only recently discovered this system, and in future hope to use it for cancer treatments and to <a href="https://www.nobelprize.org/prizes/chemistry/2020/press-release/">cure genetic conditions</a>. It has already been used to make <a href="https://www.frontiersin.org/articles/10.3389/fcimb.2021.663949/full">COVID-19 detection tests</a>.</p>
<p>Some people think of ants as tiny insects barely worth thinking about. But ants from the species <em>Megaponera analis</em>, found in sub-Saharan Africa, are <a href="https://www.science.org/doi/10.1126/sciadv.1602187">talented surgeons</a>. These warrior ants specialise in raiding termite nests. The larger ants, majors, break termites’ defensive mud barriers, then their smaller colleagues, minors, rush through these openings to pull termites out of the nest.</p>
<p>After the raids, the ants form orderly columns again and majors carry dead termites back to the ant nest. But entomologists noticed that some majors also transport injured ants, while others treat their comrades’ wounds with antimicrobial chemicals secreted by <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1634922/">fellow ants’ glands</a>.</p>
<p>The ants also use their powerful mandibles to remove termites that are clinging to warrior ant bodies by their teeth, and to stitch wounds. These ant surgeons were so effective that patients were spotted on the battlefield the next day.</p>
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<h2>Successful farmers</h2>
<p>Farming in the way humans know it is planting, protecting and harvesting crops for nourishment. Research shows that the soil fungus <em>Morchella crassipes</em> also <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2013.2242">does this to the bacteria <em>Pseudomonas putida</em></a> for its carbon, which the soil fungus needs to grow. </p>
<p><a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2022.1458">In turn, ambrosia beetles transport fungus spores</a> in a pouch-like structure in their gut to tunnels bored into trees. Ambrosia fungi produce asexual fruit only in the presence of the beetles. This fruit is their sole food source, and the beetles even remove “weed” fungus. </p>
<p>Leafcutter ants <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5118115/">also farm fungi from the genus <em>Leucoagaricus</em></a>, and even use antibiotic bacteria to <a href="https://www.nature.com/articles/19519">protect their crops from parasites</a>. Ants don’t just stick to agriculture, though; they herd aphids too. Just as we humans milk cows, <a href="https://www.youtube.com/watch?v=NJmCKaX0AGg">ants “milk” aphids</a> for the nutritious honeydew they produce. </p>
<p>So, these tiny beings were all farmers millions of years before humans had even thought of it.</p>
<p>Human civilisation is the most recent addition to an ever-changing landscape of ancient societies. Learning to value nonhuman civilisations may help reveal the ancient wisdom of species that preceded us. In so doing, this newly discovered wisdom could help us resolve the environmental crisis caused by our civilisation.</p><img src="https://counter.theconversation.com/content/203450/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Predrag Slijepcevic received funding from various organisations including Department of Health, EU, Royal Society and British Council. He is the author of Biocivilisations: A New Look at the Science of Life (Chelsea Green Publishing).</span></em></p>Ants are skilled surgeons, bacteria have their own internet, and scientists think sperm whales have names.Predrag Slijepcevic, Senior Lecturer in Biology, Brunel University LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1889562023-03-13T12:26:33Z2023-03-13T12:26:33ZSmell is the crucial sense that holds ant society together, helping the insects recognize, communicate and cooperate with one another<figure><img src="https://images.theconversation.com/files/513805/original/file-20230306-20-apwc3a.jpg?ixlib=rb-1.1.0&rect=0%2C1224%2C2696%2C1582&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ants from different colonies will fight based on smell alone.</span> <span class="attribution"><span class="source">Joseph Howell, Vanderbilt University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Ants can be found in <a href="https://doi.org/10.1038/s41467-018-04218-4">nearly every location on Earth</a>, with rough estimates suggesting there are <a href="https://www.bbc.com/news/magazine-29281253">over 10 quadrillion individuals</a> – that is a 1 followed by 16 zeroes, or about 1 million ants per person. Ants are among the most biologically successful animals on the planet. </p>
<p>A surprising part of their evolutionary success is the amazing sense of smell that lets them recognize, communicate and cooperate with one another.</p>
<p>Ants live in complex colonies, sometimes referred to as nests, that are home to <a href="https://wwnorton.com/books/9780393067040">a wide range of social interactions</a>. Here, one or more queens are responsible for all the reproduction within that colony. The vast majority of colony members are female workers – sisters that never mate or reproduce and live only to serve the group.</p>
<p>Ants need to <a href="https://doi.org/10.1186/s12915-022-01505-x">defend their colony</a>, <a href="https://doi.org/10.1371/journal.pone.0052219">seek food</a> and <a href="https://doi.org/10.1086/690840">take care of offspring</a>. To accomplish these tasks some ant species domesticate other insects, while others create agricultural systems, harvesting leaves from which they <a href="https://doi.org/10.1086/661128">grow edible fungal gardens</a>. Successfully coordinating all these intricate tasks requires reliable and secure communication among nestmates.</p>
<p><a href="https://scholar.google.com/citations?user=PrNrnI8AAAAJ&hl=en&oi=sra">We</a> <a href="https://scholar.google.com/citations?hl=en&user=IZUwOQ0AAAAJ">are</a> biologists who study the remarkable sensory abilities of ants. <a href="https://lab.vanderbilt.edu/zwiebel-lab/">Our recent work</a> shows how their societies depend on the exchange of reliable information which, if disrupted, spells doom for their colonies.</p>
<h2>Unique scents</h2>
<p>Human communication relies primarily on verbal and visual cues. We usually identify our friends by the sound of their voice, the appearance of their face or the clothes they wear. Ants, however, <a href="https://doi.org/10.1242/jeb.215400">rely primarily on their acute sense of smell</a>. </p>
<p>An exterior shell, known as an exoskeleton, encases an ant’s body. This greasy coat carries a unique scent that varies from individual to individual and gives each ant a <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674040755">unique odor signature that other ants can detect</a>. This odor signature can communicate important information. </p>
<p>The queen, for example, will smell slightly different from a worker, and thus receive special treatment within the colony. Importantly, ants from different colonies will smell slightly different from one another. The detection and decoding of these differences is <a href="https://doi.org/10.3389/fnbeh.2018.00191">vital for colony defense</a> and can trigger aggressive turf wars between colonies when ants catch a whiff of intruders.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/-ZFWVCkBcxI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Interactions between nestmates are friendly. But when ants sniff out enemy non-nestmates, there is rapid and deadly aggression. Produced by the Zwiebel Lab, Vanderbilt University, filmed by Stephen Ferguson.</span></figcaption>
</figure>
<p>For ants and other insects, receiving chemical information begins when an odor enters the small hairs located along their antennae. These hairs are hollow and contain <a href="https://doi.org/10.1016/j.cois.2014.10.006">special receptors, called chemosensory neurons</a>, that sort and send the chemical information to the ant’s brain. </p>
<p>Odors, such as those given off from an ant’s greasy coat, <a href="https://doi.org/10.1242/jeb.215400">act like chemical “keys</a>.” Ants can smell these odor keys only if they are inserted into the correct set of chemosensory neuron “locks.” A neuronal lock remains shut to any odors except its particular key. When the correct key binds to the correct neuronal lock, though, the receptor sends a complex message to the brain. The ant’s brain is able to decode this sensory information to make decisions that ultimately lead to cooperation between nestmates – or battles between non-nestmates. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A Tupperware container filled with ants. Three test tubes with cotton stoppers appear to hold water." src="https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/514327/original/file-20230308-22-8r9eol.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A colony of carpenter ants (<em>Camponotus floridanus</em>) reared in the Zwiebel Lab at Vanderbilt University.</span>
<span class="attribution"><span class="source">LJ Zwiebel, Vanderbilt University</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Changing the locks</h2>
<p>To better understand how ants detect and communicate information, we use laboratory tools such as <a href="https://doi.org/10.1242/jeb.215400">precisely targeted drugs</a> and <a href="https://doi.org/10.1016/j.cell.2017.06.051">genetic</a> <a href="https://doi.org/10.1016/j.cell.2017.07.001">engineering</a> to manipulate their sense of smell. We are especially interested in what happens when an ant’s sense of smell goes wrong. </p>
<p>For example, when we prevent an odor “key” from opening a chemosensory “lock,” it prevents the chemical information from reaching the brain. This would be like plugging your nose or standing in a completely dark room – no scents or sights would register. We can also open all the “locks” at the same time, which floods the neurons with too many messages. Both of these scenarios dramatically compromise an ant’s ability to detect and receive accurate information.</p>
<p>When we messed with ants’ sense of smell – whether shutting down or flooding their odor receptors – we found <a href="https://doi.org/10.1242/jeb.215400">they no longer attacked non-nestmates</a>. Instead, they became less aggressive. In the absence of clear information, ants exercised restraint and opted to accept rather than attack their fellow ant. Put another way, ants ask questions first and shoot later. </p>
<p>We believe this social restraint is hard-wired and gives ants an evolutionary advantage. When you live in a colony with tens of thousands of sisters, a simple case of mistaken identity or miscommunication could lead to deadly infighting and societal chaos, which is potentially very costly.</p>
<p>When ants in our experiments lose their sense of smell, and their ability to detect accurate information becomes compromised, <a href="https://doi.org/10.1016/j.cell.2017.06.051">they no longer stick together</a> <a href="https://doi.org/10.1016/j.cell.2017.07.001">in a cohesive colony</a>. </p>
<p>Not only do they fail to recognize and attack foes, they also stop cooperating with their friends. Without nurses to take care of the young or foragers to collect food, the eggs dry up and the queen goes hungry. </p>
<p>We discovered that without an accurate means of communicating and receiving chemical information, ant societies collapse and the colony quickly dies. Miscommunication or the lack of accurate information <a href="https://www.pbs.org/newshour/nation/miscommunication-blamed-deadly-u-s-mistake-afghanistan">affects other highly social animals, including humans</a>, as well. For ants, it all depends on their sense of smell.</p><img src="https://counter.theconversation.com/content/188956/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laurence Zwiebel currently receives funding from the NIH and Vanderbilt University. </span></em></p><p class="fine-print"><em><span>Stephen Ferguson currently receives funding from the NIH and Vanderbilt University.</span></em></p>Researchers explore what happens when ants can’t properly use smell to detect friend from foe.Laurence Zwiebel, Professor of Biological Sciences and of Pharmacology, Vanderbilt UniversityStephen Ferguson, Postdoctoral Scholar in Biological Sciences, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2008792023-03-02T16:55:41Z2023-03-02T16:55:41ZAnimal architecture: why we need to design buildings for wildlife as well as people<p>How did early humans first learn to build? It’s quite possible that it was by <a href="https://www.google.co.uk/books/edition/The_Ten_Books_on_Architecture/iu9-WP-5GYAC?hl=en&gbpv=1&printsec=frontcover">observing animals</a> that had already mastered the art. Indeed, when you look at the animal world many birds, insects and mammals are excellent architects and builders.</p>
<p>Beavers are quite literally landscape engineers – they’re being <a href="https://www.theguardian.com/commentisfree/2022/oct/11/beavers-britain-climate-crisis-england-protecting-rivers">reintroduced</a> in the UK to help fight against the increased incidence and severity of flooding caused by climate change. </p>
<p>Social insects like <a href="https://www.youtube.com/watch?v=-Blqi5qcGlE">bees</a>, <a href="https://theconversation.com/wasps-why-i-love-them-and-why-you-should-too-155982">wasps</a>, <a href="https://theconversation.com/in-defence-of-ants-186220">ants</a> and <a href="https://theconversation.com/lets-mimic-termite-nests-to-keep-human-buildings-cool-115534">termites</a> construct what many have described as the animal equivalents of human cities. </p>
<p><a href="https://theconversation.com/spider-legs-build-webs-without-the-brains-help-providing-a-model-for-future-robot-limbs-153561">Spiders</a> and silkworms have long been regarded as expert builders in the <a href="https://theconversation.com/why-we-cant-spin-a-silken-yarn-as-strong-as-a-spider-can-71003">weaving of their silk webs</a>. While other creatures like <a href="https://www.youtube.com/watch?v=uIR_vSRASxM">foxes</a>, <a href="https://www.livescience.com/52297-moles.html">moles</a> and <a href="https://badgerwatcher.com/2010/02/21/how-to-recognise-a-badger-sett/">badgers</a> build by excavating the ground. </p>
<p>Then there are the animals that carry their homes on their backs – the shells of <a href="https://theconversation.com/curious-kids-what-is-snail-slime-and-why-is-it-shiny-192424">snails</a> and <a href="https://theconversation.com/how-did-the-turtle-get-its-shell-fossil-discovery-gives-us-a-clue-43800">turtles</a>, for example, are both extensions of and protection for their vulnerable soft bodies.</p>
<h2>Beyond human</h2>
<p>We might <a href="https://theconversation.com/meerkats-how-we-used-radar-to-reveal-the-underground-maze-they-call-home-90878">admire and even imitate</a> animal architecture, but when it comes to human-designed buildings, we are usually extremely selective about what kinds of creatures we allow in. </p>
<p>In general, animals are only ever designed for when they are of use to humans – whether as livestock, domestic pets, spectacles to consume in zoos and aquariums, or objects of scientific manipulation in laboratories. </p>
<p>If animals can’t be put to use, they’re usually ignored. And if those animals take it upon themselves to <a href="https://theconversation.com/how-the-red-fox-adapted-to-life-in-our-towns-and-cities-77439">inhabit buildings</a>, they’re invariably regarded as <a href="https://theconversation.com/super-rats-or-sickly-rodents-our-war-against-urban-rats-could-be-leading-to-swift-evolutionary-changes-125902">pests</a> and dealt with accordingly.</p>
<p>In my new book, <a href="https://reaktionbooks.co.uk/work/animal-architecture">Animal Architecture: Beasts, Buildings and Us</a>, I look at why we should build for animals as well as people. Indeed, wildlife is all around us and is already living in or around most of our homes, anyway. </p>
<p>Examples in the book include spiders spinning their webs in the dark corners of rooms. Swallows finding ideal purchase on brick walls for their saliva and mud-based nest cups. Rats making their homes in the subterranean spaces of the city. And cats and dogs appropriating our furniture and fittings as their own places of rest. </p>
<p>There’s hardly any part of the human-built environment that can’t be inhabited or changed by insects, animals and birds. It’s easy enough to understand how this works in relation to animals that are classed as pets. It’s generally taken for granted that pet owners know how to care for their animals. But it’s much harder to care for animals that are mostly regarded as unwelcome intruders into buildings. </p>
<h2>Animal estates</h2>
<p>A powerful example of the potential breadth of such interspecies awareness is artist Fritz Haeg’s <a href="https://www.fritzhaeg.com/garden/initiatives/animalestates/main2.html">Animal Estates</a> project, which ran from 2008 until 2013. In nine different cities, Haeg organised events to encourage participation in creating structures that would be attractive to a variety of native species, including bats, birds and insects. </p>
<p>As well as building structures for animals to inhabit, the project also hosted events designed to stimulate interest and knowledge about native animals (and, in many cases, to encourage urban dwellers to make structures themselves). This holistic approach to ecological design aimed to foster more care for animals in cities – animals that would probably otherwise go unnoticed. </p>
<p>Other wildlife-inspired architectural projects include the non-profit organisation <a href="http://www.expandedenvironment.org/aboutanimalarchitecture/">The Expanded Environment</a>, which provides helpful online resources on how to care for a much wider range of animals in relation to architecture – most notably in their collaborative design proposals and annual competitions for novel types of animal design. </p>
<p>The material on their website expands ideas about what might be considered appropriate animals for designers to work with as “clients”. Insects appear alongside dogs and cats, birds with lizards and bats with oysters.</p>
<h2>Housing the non-human</h2>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Tower that houses bats" src="https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=878&fit=crop&dpr=1 600w, https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=878&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=878&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1103&fit=crop&dpr=1 754w, https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1103&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/512897/original/file-20230301-24-4ic5cs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1103&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A contemporary reconstruction of Charles A. Campbell’s Municipal Bat House (1914), near Comfort, Texas, 2009.</span>
<span class="attribution"><span class="source">Wikimedia Commons, Larry D. Moore/cc-by-sa 4.0 International</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Ultimately thinking beyond just people is important because all lifeforms create their own environments – and what humans generally call “the environment” is in reality the sum of these creations. Why then does the idea that humans live outside of the environment persist so strongly? </p>
<p>Perhaps, as any therapist will likely tell you, losing a fantasy is always much harder than losing a reality. Yet, as is all too obvious, the persistence of the fantasy of <a href="https://psyche.co/ideas/human-exceptionalism-imposes-horrible-costs-on-other-animals">human exceptionalism</a> is now endangering all life on the planet. </p>
<p>It is humans, and humans alone, who dominate every corner of the environment, while at the same time asserting they are actually removed from that environment. If my book has one core aim, it is to encourage readers to think beyond humans in the way we imagine, design and live in our buildings and cities.</p><img src="https://counter.theconversation.com/content/200879/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Dobraszczyk does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Our lives are intertwined with animals, insects and birds – we should consider them more when we design our cities.Paul Dobraszczyk, Lecturer in Architecture, UCLLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2005302023-03-01T19:05:47Z2023-03-01T19:05:47ZFrom deadly jaws and enormous strength to mushroom farming, Ant-Man is only tapping into a portion of the real superpowers of ants<figure><img src="https://images.theconversation.com/files/512774/original/file-20230228-4992-va1d92.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1278%2C720&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Disney</span></span></figcaption></figure><p><a href="https://en.wikipedia.org/wiki/Ant-Man_and_the_Wasp:_Quantumania">Ant-Man and The Wasp: Quantumania</a> is the latest film in the ever-expanding Marvel Cinematic Universe. </p>
<p>The ant-filled film follows the adventures of Scott Lang (AKA Ant-Man), Hope Van Dyne (AKA The Wasp) and Cassie Lang (AKA The Stinger), who all use science-derived technology to give them ant-like powers. In the Ant-Man films, Ant-Man also has the ability to direct the actions of several ant species, each with its own unique set of characteristics. </p>
<p>Tiny ants might seem like unlikely inspirations and sidekicks for a superhero, but real-life ants have astonishing superpowers that make them formidable allies. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/5WfTEZJnv_8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>Super strength</h2>
<p>Ant-Man and The Wasp both wear suits that allow them to shrink and also give them the proportionate strength of an ant. </p>
<p>Ants are well known for their super-strength, with some workers being able to carry up to 50 times their own body weight. Since ants – like other insects – have their skeletons on the outside, their muscles do not have to support much of their body weight, leaving them free to apply more strength to lifting. </p>
<p>In addition, smaller animals tend to have greater strength relative to their body weight. Even ants’ joints are strong: the <a href="https://www.insidescience.org/news/ants-are-even-stronger-you-imagine">neck joints</a> of the common field ant <em>Formica exsectoides</em> can withstand <a href="https://theconversation.com/how-do-olympic-athletes-stack-up-against-invertebrates-not-very-well-164488">5,000 times the ant’s body weight</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-do-olympic-athletes-stack-up-against-invertebrates-not-very-well-164488">How do Olympic athletes stack up against invertebrates? Not very well</a>
</strong>
</em>
</p>
<hr>
<h2>Super speed</h2>
<p>Ant-Man and The Wasp don’t have super speed – but real-life ants certainly do!</p>
<p>Saharan silver ants (<em><a href="https://www.google.com/url?q=https://www.nationalgeographic.com/animals/article/silver-saharan-ants-fastest-desert%23:%7E:text%3DThese%2520Saharan%2520silver%2520ants%2520are,body%2520length%2520in%2520a%2520second&sa=D&source=docs&ust=1677127817128278&usg=AOvVaw17D5WG1G8tPb5pDi-hveOj">Cataglyphis bombycina</a></em>) can travel 100 times their body length in a second, making them one of the fastest animals on the planet. That’s like a 180-centimetre human running at 200 metres per second (or 720km per hour)! <a href="https://www.google.com/url?q=https://olympics.com/en/news/usain-bolt-record-world-champion-athlete-fastest-man-olympics-sprinter-100m-200m&sa=D&source=docs&ust=1677127817131145&usg=AOvVaw0S40Y9h6wLlUd15o1LgCf1">Usain Bolt</a>, the all-time fastest person in the world, could only hit a maximum speed of 47km per hour.</p>
<p>Ants are not just fast runners – they can move other parts of their bodies with mind-boggling speed. Trap jaw ants (<em>Odontomachus bauri</em>) can slam their jaws shut at an incredible <a href="https://www.pnas.org/doi/10.1073/pnas.0604290103">137km per hour</a>, one of the fastest movements in the animal kingdom. Trap jaw ants use their <a href="https://www.youtube.com/watch?v=H2okI6ZszQY">super-fast mandibles</a> to catch their favourite prey: termites. </p>
<p>The jaws of trap jaw ants are also impressive defensive weapons and can be used to stun attacking predators such as spiders. These ants can even make a rapid retreat by striking their jaws against the ground. This “bouncer defence” throws the ant an astonishing 8cm into the air, the equivalent of an average-sized human jumping 40 metres.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/512776/original/file-20230301-4933-hdsbr3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Trap jaw ants (Odontomachus bauri).</span>
<span class="attribution"><span class="source">Wikimedia Commons</span></span>
</figcaption>
</figure>
<h2>Strength in numbers</h2>
<p>What ants lack in size, they make up for in sheer numbers. A recent study estimated that there are more than <a href="https://www.google.com/url?q=https://www.smithsonianmag.com/smart-news/an-estimated-20-quadrillion-ants-live-on-earth-180980804/&sa=D&source=docs&ust=1677127817132195&usg=AOvVaw2WM3_yrDLicX1LZiYAJ7iA">20 quadrillion</a> ants alive at any one time – there are many more ants on Earth than stars in the Milky Way galaxy. </p>
<p>Argentine ants (<em>Linepithema humile</em>) build some of the largest supercolonies on Earth, containing billions of workers spread over <a href="https://www.pnas.org/doi/10.1073/pnas.092694199#:%7E:text=In%20the%20case%20of%20the,nests%20comprising%20billions%20of%20workers.">6,000 square kilometres</a>.</p>
<p>By working together in overwhelming numbers, ants can successfully attack animals many times bigger than themselves. Army ant swarms can take down <a href="https://www.youtube.com/watch?v=JsfiUR0ZzLw">large prey</a> such as lizards, frogs and even scorpions. Like the Ant-Man comic character Cassie Lang, some ant species possess a stinger capable of delivering painful venom. South American bullet ants (<em>Paraponera clavata</em>) have one of the <a href="https://www.nhm.ac.uk/scroller-schmidt-painscale/#14">world’s most painful stings</a>. It’s no wonder they were featured as “attack ants” in the first Ant-Man movie.</p>
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<h2>No leaders necessary</h2>
<p>Throughout the Ant-Man films, the heroes use communication devices to lead colonies of ants. However, there are no leaders in a real ant colony. </p>
<p>Worker ants are responsible for tasks such as hunting, cleaning and rearing larvae, while queens lay eggs to keep the colony stocked with workers. You might think a society containing millions of tiny-brained animals with no leader would be chaos, but by working together, ants can achieve feats that far exceed the brain power of any individual – this is called “swarm intelligence”. </p>
<p>Argentine ants, for example, can find the <a href="https://cosmosmagazine.com/nature/animals/building-better-transport-systems-lessons-from-ants-and-fungi/">shortest path between nests</a>, while fire ants escape flooding by linking their bodies together to form enormous <a href="https://www.youtube.com/watch?v=MJ4IjC512bg">living life rafts</a>. In the First Ant-Man movie, Scott Lang uses the coordinated skills of fire ants to break into Pym Headquarters.</p>
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<h2>Super sized societies</h2>
<p>In the latest movie, a colony of ants accidentally enters the mysterious quantum realm where they undergo 1,000 years of evolution, resulting in a society of highly intelligent ants living in a futuristic society. </p>
<p>But modern-day ants have already evolved exceptionally complex societies. Some ant species have even evolved forms of agriculture by <a href="https://www.nationalgeographic.com/science/article/ants-herd-aphids-with-tranquilisers-in-their-footsteps">tending to and protecting herds of sap-sucking aphids</a>. Aphids respond to their ant farmers by producing droplets of a sugary substance called “honeydew” which the ants harvest as food. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/tiny-game-of-thrones-the-workers-of-yellow-crazy-ants-can-act-like-lazy-wannabe-queens-so-we-watched-them-fight-158426">Tiny Game of Thrones: the workers of yellow crazy ants can act like lazy wannabe queens. So we watched them fight</a>
</strong>
</em>
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<p>Amazingly, leaf cutter ants in South America care for immense underground <a href="https://www.nationalgeographic.com/science/article/how-leafcutter-ants-evolved-from-farmers-into-cows">fungi gardens which they grow for food</a>. The ants feed the fungus leaves and are able to select the leaf species that maximise fungal growth. Ants weed the garden by removing weedy fungi species, and can even use <a href="https://www.smithsonianmag.com/smart-news/new-antibiotics-humans-could-come-ant-fungus-gardens-180956300/">antibiotics</a> to protect the fungi from disease.</p>
<p>Given their super strength, incredible speeds and amazing swarm intelligence, Ant-Man is lucky to have ants on his side!</p><img src="https://counter.theconversation.com/content/200530/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tanya Latty receives funding from The Australian Research Council and AgrifFutures Australia. She is affiliated with Invertebrates Australia, a conservation organization dedicated to the conservation of insects and other invertebrates. </span></em></p><p class="fine-print"><em><span>Caitlyn Forster receives funding from The Australian Research Council.</span></em></p>Tiny ants might seem like unlikely inspirations and sidekicks for a superhero, but real life ants have astonishing superpowers that make them formidable allies.Tanya Latty, Associate professor, University of SydneyCaitlyn Forster, Associate Lecturer, School of Life and Environmental Sciences, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1862752023-01-13T13:30:36Z2023-01-13T13:30:36ZNative eastern fence lizards changed their bodies and behavior in response to invasive red imported fire ants<figure><img src="https://images.theconversation.com/files/503699/original/file-20230109-5266-ezc4go.jpg?ixlib=rb-1.1.0&rect=191%2C97%2C2151%2C1645&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lizards that do or do not share space with invasive fire ants will react differently to this scenario. </span> <span class="attribution"><span class="source">Tracy Langkilde and Travis Robbins</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>An eastern fence lizard basking in the sun feels a small red ant walk over its back. Not hungry, it ignores the insect. Soon there are lots of ants crawling up its legs, biting the scales that usually protect it and inserting their stingers in its soft underlying flesh.</p>
<p>Not having evolved with this threat, the lizard adopts its typical defensive posture of lying flat and closing its eyes, counting on its natural camouflage to protect it. This can be a deadly decision, though. As few as 12 of these ants can kill an adult lizard in <a href="https://doi.org/10.1890/08-0355.1">less than a minute</a>.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="lizard clings to a vertical fence post" src="https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503701/original/file-20230109-8020-tpch1g.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A male fence lizard showing off his throat and abdominal badges.</span>
<span class="attribution"><span class="source">Tracy Langkilde</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Such interactions are now common in the southeastern United States, where native animals such as eastern fence lizards (<em>Sceloporus undulatus</em>) have <a href="https://doi.org/10.1890/08-0355.1">shared their habitat</a> with the invasive red imported fire ant (<em>Solenopsis invicta</em>) for decades.</p>
<p><a href="https://scholar.google.com/citations?user=4fYdo1MAAAAJ&hl=en&oi=ao">Our</a> <a href="https://scholar.google.com/citations?user=4vr-wR8AAAAJ&hl=en&oi=ao">research</a> <a href="http://langkildelab.com">group</a> has been studying the interactions between these two species and how they change over time. These small lizards, about 6 inches (15 centimeters) from nose to the tip of the tail, have been native to the southeastern United States <a href="https://doi.org/10.2307/1562904">for thousands of years</a>. Invasive red imported fire ants are originally from South America but were unintentionally introduced to the port of Mobile, Alabama, in the 1930s and have steadily spread northward – into the lizards’ territory – since their introduction.</p>
<p>We’re particularly interested in how animals may adapt to coexist with venomous species. The fire ants’ well-documented path of invasion, and the fact that they are currently restricted to just a portion of the lizards’ range, allows us to compare how lizards from ecologically similar areas differ based on the presence or absence of these fire ants. Overall it seems the lizards are learning to live with the invaders, adapting their behavior and bodies to better survive attacks from the ants and using them as a new food source.</p>
<h2>Changing looks and behavior to survive attacks</h2>
<p>Lizards and fire ants require a similar habitat to survive – open and often disturbed patches of land that let in sunlight. We’ve found that lizards <a href="https://doi.org/10.1139/Z09-053">don’t avoid areas</a> where fire ants are and they don’t avoid their scent. It would be difficult to do, anyway, given how ubiquitous these ants are – within the areas they’ve invaded, fire ant mounds can dot the landscape every few meters.</p>
<p>Foraging fire ants can locate a basking lizard within minutes and quickly <a href="https://doi.org/10.1093/beheco/ars011">recruit other ants</a> to attack. All is not lost for the lizard, however. Some do what you probably would when attacked by fire ants: flick them off and move away. This twitch-and-flee behavior <a href="https://doi.org/10.1093/beheco/ars011">removes scout ants</a>, preventing them from recruiting reinforcements, and also gets rid of any other ant attackers.</p>
<p>This behavior is common in baby fence lizards, which are vulnerable even to native ants, but is usually lost in adults as they outgrow threats from native ants by getting larger. However, in areas with fire ants, <a href="https://doi.org/10.1890/08-0355.1">adult lizards retain this behavior</a> that <a href="https://doi.org/10.1111/gcb.14510">better enables them to</a> <a href="https://doi.org/10.1093/beheco/ars011">survive fire ant attack</a>.</p>
<p>Lizards can’t tell whether they have a potentially deadly fire ant crawling on them or if it’s something harmless like a fly. So, to be safe, they respond in the same way to anything that they <a href="https://doi.org/10.1016/j.anbehav.2016.11.006">feel climbing on their scales</a>. Unfortunately, this shake-it-off behavior doesn’t solve all the lizards’ problems, since it breaks their usual camouflage, making them more obvious to visual predators like birds. We have observed <a href="https://doi.org/10.1016/j.anbehav.2016.11.006">more evidence of wounds</a> in fire ant-adapted lizards. And a lizard that survives a fire ant attack can still <a href="https://doi.org/10.1071/WR10098">die weeks to months later</a>, though we’re not sure yet why.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="fingers hold a transparent ruler up to a lizard's extended rear leg" src="https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503698/original/file-20230109-9349-lxdmaf.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Careful measurements in the field find longer legs in lizard populations exposed to fire ants.</span>
<span class="attribution"><span class="source">Nisha Ligon</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>We find lizard populations that have been living with fire ants have adapted <a href="https://doi.org/10.1670/11-002">to have longer legs</a>, <a href="https://doi.org/10.1111/gcb.14510">which are better at removing fire ants</a> when a lizard twitches and flees. This is a big shift for this species, reversing the <a href="https://doi.org/10.1111/gcb.14510">latitudinal pattern</a> we see in museum specimens – lizards tend to have shorter limbs the closer the population is to the equator. Since limb length can have important implications for how animals move around their environment, this anatomical change could have <a href="https://doi.org/10.1016/S1095-6433(01)00469-X">important consequences</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="front half of a lizard with part of an ant's body coming out of its mouth" src="https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=424&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=424&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=424&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=533&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=533&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503700/original/file-20230109-9211-auh4va.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=533&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Potentially dangerous venomous stings don’t stop these lizards from learning to make a meal of the invasive fire ants.</span>
<span class="attribution"><span class="source">Tracy Langkilde and Travis Robbins</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Venomous predator can also be prey</h2>
<p>These lizards, especially when they are young, eat a lot of ants of various types. Eating a fire ant, though, can mean getting stung inside the mouth, which can make this a <a href="https://doi.org/10.1002/jez.570">lethal meal</a>. Baby lizards quickly learn to avoid eating fire ants, but this leads to their also <a href="https://doi.org/10.1007/s10530-019-01949-3">avoiding their native ant diet</a>, the consequences of which are unknown.</p>
<p>Adult lizards, on the other hand, are less vulnerable to succumbing to consumed fire ants and take advantage of this <a href="https://doi.org/10.1007/s00442-016-3596-3">new</a> <a href="https://doi.org/10.1007/s10530-012-0295-9">food</a> <a href="https://doi.org/10.1111/j.1420-9101.2012.02583.x">source</a>. So there’s an upside to these troublesome insect invaders for fence lizards.</p>
<h2>Physiological changes triggered by fire ants</h2>
<p>Lethal outcomes are the most striking consequence of interactions between fire ants and fence lizards, but that’s not the full story.</p>
<p>As you might imagine – or even have experienced – being stung by fire ants is stressful for lizards, as indicated by an <a href="https://doi.org/10.1086/689983">increase in a stress-relevant glucocorticoid hormone</a> following attack, just as you would experience after getting a scare.</p>
<p>We find that lizards that frequently experience fire ant attacks have a different “stress profile.” They have <a href="https://doi.org/10.1111/gcb.14510">higher</a> <a href="https://doi.org/10.1016/j.ygcen.2011.12.027">concentrations</a> of this stress hormone even while at rest. They show <a href="https://doi.org/10.1016/j.yhbeh.2016.11.010">greater</a> <a href="https://doi.org/10.1016/j.ygcen.2011.12.027">increases</a> in glucocorticoids in response to a stressor and have <a href="https://doi.org/10.1093/beheco/arab099">different</a> <a href="https://doi.org/10.1016/j.yhbeh.2011.04.001">behavioral</a> and <a href="https://doi.org/10.1093/biolinnean/blz154">immune</a> <a href="https://doi.org/10.1242/jeb.188359">responses</a> to glucocorticoid exposure. While stress gets a bad rap, these hormones play an important role and in this case can trigger survival-enhancing <a href="https://doi.org/10.1890/08-0355.1">behavioral</a> <a href="https://doi.org/10.1093/beheco/ars011">responses</a> to <a href="https://doi.org/10.1016/j.anbehav.2009.10.028">fire</a> <a href="https://doi.org/10.1111/gcb.14510">ants</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ekfdDEivgAI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Eating fire ants is almost like getting a vaccine against their stings for lizards.</span></figcaption>
</figure>
<p>Lizards living with fire ants show <a href="https://doi.org/10.1002/jez.2418">changes to their immune systems</a>. They have elevated levels of IgM antibodies that respond to fire ants and higher levels of a type of white blood cell that can help <a href="https://doi.org/10.1016/j.alit.2015.09.002">neutralize venom toxins</a>. They also have decreased levels of other immune system components. Together, these immune differences may allow lizards to better coexist with fire ants, with the elevated immune measures being particularly useful when dealing with stings. Tailoring the immune system to survive fire ant attacks may, however, leave lizards more vulnerable to other immune challenges, such as viruses.</p>
<p>Getting stung over a period of time stimulates lizards’ skin immunity, which could guard against effects of skin damage. Additionally, feeding on fire ants that we’ve rendered in the lab incapable of stinging <a href="https://doi.org/10.1007/s10530-022-02939-8">increases some immune measures</a> in the lizards above what we see in lizards that were stung by fire ants. This bolstered immunity may then help lizards survive future stings. We think the elevated immunity we see in wild lizards in fire ant-invaded places may be caused by consumption of fire ants.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="lizard missing a front foot" src="https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=376&fit=crop&dpr=1 600w, https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=376&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=376&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/503702/original/file-20230109-6779-g7lf20.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Injuries like this one to a forelimb appear to be more common in lizard populations that have adapted to the fire ants.</span>
<span class="attribution"><span class="source">Christopher Thawley</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Animals adapt – but there can be consequences</h2>
<p>The effects of invasive fire ant and eastern fence lizard interactions demonstrate how species can adapt to survive the presence of invasive predators. Behavioral shifts can allow animals to avoid or escape attack, and changes in morphology can make these strategies more effective. And eating venomous prey may provide immune protection against subsequent attack.</p>
<p>However, this research also illustrates that adaptations are not a panacea. While adapting to a changing world is clearly critical for survival, by its very nature this changes animals, pushing them off their original evolutionary trajectory and leaving them vulnerable to new threats. Getting a full picture of the consequences of the presence of a new threatening species, and of the changes that animals may need to make to survive them, is critical if scientists are going to be able to predict and manage the impact of invasive species on native communities.</p><img src="https://counter.theconversation.com/content/186275/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Funding was provided in part by the National Science Foundation.</span></em></p><p class="fine-print"><em><span>Tracy Langkilde receives funding from The Pennsylvania State University. </span></em></p>The ways eastern fence lizards have changed in response to red imported fire ants demonstrate how species can adapt to survive the presence of invasive predators.Catherine Tylan, Postdoctoral Researcher in Biology, Penn StateTracy Langkilde, Professor of Biology and Verne M. Willaman Dean, Eberly College of Science, Penn StateLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1934472022-11-23T00:10:19Z2022-11-23T00:10:19ZThey might not have a spine, but invertebrates are the backbone of our ecosystems. Let’s help them out<p>Many of Australia’s natural places are in a poor state. While important work is being done to protect particular species, we must also take a broader approach to returning entire ecosystems to their <a href="https://www.science.org/doi/full/10.1126/science.aav5570">former glory</a> – a strategy known as “rewilding”. </p>
<p>Rewilding aims to <a href="https://www.sciencedirect.com/science/article/pii/S0169534716000628">restore</a> the complex interactions that make up a functioning ecosystem. It involves reintroducing long-lost plants and animals to both conserve those species and restore an area’s natural processes.</p>
<p>You might imagine this involves an ecologist releasing cute, furry bilbies, or an endangered songbird. This is a logical assumption. Research <a href="https://www.cambridge.org/core/journals/oryx/article/bias-and-dispersal-in-the-animal-reintroduction-literature/BAB3FC3B2FE61B60CDC4273373624569">shows</a> a marked bias in reintroduction programs towards vertebrates, especially birds and mammals. </p>
<p>Meanwhile, invertebrates are often overlooked. But <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2779">our new research</a> shows rewilding with invertebrates – insects, worms, spiders and the like – can go a long way in bringing our degraded landscapes back to life.</p>
<figure class="align-center ">
<img alt="spider in web in front of tree" src="https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496877/original/file-20221122-18-aq9k9d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Invertebrates are crucial to functioning ecosystems.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A shocking decline</h2>
<p>Invertebrates <a href="https://www.science.org/doi/abs/10.1126/science.241.4872.1441">make up 97% of animal life</a> and drive key processes such as pollination and cycling nutrients. But they’re the focus of <a href="https://www.cambridge.org/core/journals/oryx/article/bias-and-dispersal-in-the-animal-reintroduction-literature/BAB3FC3B2FE61B60CDC4273373624569">just 3%</a> of reintroduction projects.</p>
<p>This reflects a <a href="https://www.science.org/doi/full/10.1126/science.297.5579.191b">taxonomic bias</a> in conservation. Overseas, this has led to rewilding projects centred on <a href="https://www.pnas.org/doi/full/10.1073/pnas.1502556112">large keystone mammals</a> that alter ecosystems on a broad scale, such as wolves and bison. </p>
<p>Of course, traditional vertebrate rewilding projects are very important for ecosystem restoration. In Australia, for example, they are <a href="https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/cobi.13280">vital in restoring mammal communities</a> decimated by cats and foxes. </p>
<p>But invertebrate species are <a href="https://www.science.org/doi/full/10.1126/science.aax9931">declining at shocking rates</a> around the world, especially as climate change <a href="https://www.pnas.org/doi/10.1073/pnas.2002543117">worsens</a>. They also need our help to re-colonise new areas.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-humble-dung-beetle-engineers-better-ecosystems-in-australia-101975">How the humble dung beetle engineers better ecosystems in Australia</a>
</strong>
</em>
</p>
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<figure class="align-center ">
<img alt="man and child look on as woman releases bilby" src="https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496879/original/file-20221122-16-7k8rr1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mammal rewilding projects are very important for ecosystem restoration, but invertebrates need help too.</span>
<span class="attribution"><span class="source">Bobby-Jo Photography/AAP</span></span>
</figcaption>
</figure>
<h2>No beetle is an island</h2>
<p>Picture an island in the middle of the ocean. The further from shore it is, the more animals on the mainland will struggle to reach it – especially if they’re tiny and wingless, like many invertebrates.</p>
<p>My colleagues and I built our study around this analogy. </p>
<p>Instead of islands, our research involved six isolated patches of revegetated land on farms. And instead of an ocean, invertebrates had to cross a sea of pasture which, for many litter-dwelling invertebrates, is a barren, <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/btp.12682">unsheltered wasteland</a>.</p>
<p>The farm sites were “biologically poor”. That is, despite the habitat quality improving following revegetation, they contained lower-than-expected invertebrate biodiversity. </p>
<p>We surmised that invertebrates from surrounding “biologically rich” national parks were struggling to reach and recolonise the isolated revegetation patches. </p>
<p>Our study involved giving invertebrates a hand to find new homes. We moved leaf litter – and more than 300 invertebrates species hiding in it – from national park sites into six revegetated farm sites in central Victoria. </p>
<p>We moved litter samples several times between 2018 and 2020, over different seasons. Sites were “paired”, so a national park site was paired with a revegetated one that would have been similar had degradation had not occurred.</p>
<p>The litter community of invertebrates is incredibly complex and can be broken into three groups: macroinvertebrates (more than 5 mm), mesoinvertebrates (less than 5 mm) and microbes. We focused on mesoinvertebrates, which mostly comprise mites, ticks, ants, beetles and springtails (small, wingless arthropods).</p>
<p>We found among this group, beetles were most likely to survive and thrive in their new habitat, which was much drier than the one they left. Rove beetles did particularly well. </p>
<figure class="align-center ">
<img alt="red and black beetle on leaf" src="https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496880/original/file-20221122-18-oaiosp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Numbers of beetles – particularly the rove beetle, pictured – bounced back quickly after being moved.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Beetles are hardy little things with <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/mec.14418">strong exoskeletons</a> that protect them from drying out. In fact, as early as seven months after being moved, beetle numbers at the new sites reached levels similar to that in pristine national parks that we sourced leaf litter from.</p>
<p>We did not have the same success with other types of invertebrates. For example, springtails are a massive component of leaf litter communities in national parks. But they’re soft-bodied and dry out easily, so were more likely to die when moved to a new, drier environment. </p>
<p>Understanding why some groups are more likely to survive leaf litter transplants than others
is a vital step in the development of invertebrate rewilding. Nonetheless, our results show the relatively simple act of moving leaf litter can lead to comparatively large increases in species richness in a short time. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/photos-from-the-field-zooming-in-on-australias-hidden-world-of-exquisite-mites-snails-and-beetles-147576">Photos from the field: zooming in on Australia's hidden world of exquisite mites, snails and beetles</a>
</strong>
</em>
</p>
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<figure class="align-center ">
<img alt="ant in leaf litter" src="https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496881/original/file-20221122-24-rw8qpa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Moving leaf litter can quickly lead to comparatively large increases in species richness .</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Loving our creepy crawlies</h2>
<p><a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1002/eap.2779">Our study showed</a> how a simple method of rewilding with invertebrates can effectively reintroduce multiple species at once. This is an important finding.</p>
<p>More research into the method is needed across different types of sites and over longer timeframes. However, our method has the potential to be <a href="https://www.sciencedirect.com/science/article/pii/S0006320715300847">applied widely</a> in the fight against global invertebrate declines.</p>
<p>The method is cheap and easy. In contrast, rewilding projects involving vertebrates can be hard to execute and <a href="https://www.researchgate.net/profile/John-Kanowski/publication/329403751_Effective_conservation_of_critical_weight_range_mammals_reintroduction_projects_of_the_Australian_Wildlife_Conservancy/links/60becc2092851cb13d88cd21/Effective-conservation-of-critical-weight-range-mammals-reintroduction-projects-of-the-Australian-Wildlife-Conservancy.pdf">expensive</a>, and often require breeding animals for release.</p>
<p>Invertebrates are the bulk of terrestrial diversity and the <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/brv.12002">backbone</a> for proper ecosystem functioning. We need to start putting them at the centre of rewilding projects.</p>
<p>Our results are just one <a href="https://www.sciencedirect.com/science/article/pii/S0006320711002874">small piece in the puzzle</a>. Many <a href="https://www.science.org/doi/full/10.1126/science.aax9931">other invertebrate communities</a> will need safeguarding and restoring in the future. </p>
<p>Recent <a href="https://www.mdpi.com/2076-2615/12/14/1787">research</a> has challenged the assumption that humans naturally find vertebrates more engaging than invertebrates. We might be pleasantly surprised to find the public is as engaged with invertebrate rewilding projects as those focused on cute and cuddly critters.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/earth-harbours-20-000-000-000-000-000-ants-and-they-weigh-more-than-wild-birds-and-mammals-combined-190831">Earth harbours 20,000,000,000,000,000 ants – and they weigh more than wild birds and mammals combined</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/193447/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Contos receives funding from the Ecological Society of Australia. </span></em></p><p class="fine-print"><em><span>Heloise Gibb receives funding from the Hermon Slade Foundation and the Australian Research Council</span></em></p>New research shows rewilding with invertebrates – insects, worms, spiders and the like – can go a long way in bringing our degraded landscapes back to life.Peter Contos, PhD Candidate, La Trobe UniversityHeloise Gibb, Professor, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1889392022-11-15T13:22:40Z2022-11-15T13:22:40ZAnts – with their wise farming practices and efficient navigation techniques – could inspire solutions for some human problems<figure><img src="https://images.theconversation.com/files/494699/original/file-20221110-21-p2hi2g.jpg?ixlib=rb-1.1.0&rect=10%2C0%2C2235%2C1329&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Leafcutter ants cultivate fungus gardens that feed sprawling colonies.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/three-leafcutter-ants-carrying-leaves-close-up-royalty-free-image/200187319-004">Tim Flach/Stone via Getty Images</a></span></figcaption></figure><p>King Solomon may have gained some of his famed wisdom from an unlikely source – ants.</p>
<p>According to a <a href="https://www.jewishencyclopedia.com/articles/13842-solomon#anchor14">Jewish legend</a>, Solomon conversed with a clever ant queen that confronted his pride, making quite an impression on the Israelite king. In the biblical book of <a href="https://www.biblegateway.com/passage/?search=Proverbs%206%3A6-8&version=KJV">Proverbs (6:6-8)</a>, Solomon shares this advice with his son: “Look to the ant, thou sluggard, consider her ways and be wise. Which having no guide, overseer, or ruler, provideth her meat in the summer, and gathereth her food in the harvest.”</p>
<p>While I can’t claim any familial connection to King Solomon, despite sharing his name, I’ve long admired the wisdom of ants and have spent over 20 years <a href="https://scholar.google.com/citations?user=bnXkcNUAAAAJ&hl=en&oi=sra">studying their ecology, evolution and behaviors</a>. While the notion that ants may offer lessons for humans has certainly been around for a while, there may be new wisdom to gain from what scientists have learned about their biology.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/vG-QZOTc5_Q?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Ants have evolved highly complex social organizations.</span></figcaption>
</figure>
<h2>Lessons from ant agriculture</h2>
<p>As a researcher, I’m especially intrigued by <a href="https://doi.org/10.1093/isd/ixab029">fungus-growing ants</a>, a group of 248 species that cultivate fungi as their main source of food. They include 79 species of <a href="https://wwnorton.com/books/9780393338683">leafcutter ants</a>, which grow their fungal gardens with freshly cut leaves they carry into their enormous underground nests. I’ve excavated hundreds of leafcutter ant nests from Texas to Argentina as part of the scientific effort to understand how these ants coevolved with their fungal crops.</p>
<p>Much like human farmers, each species of fungus-growing ant is very particular about the type of crops they cultivate. Most varieties descend from a type of fungus that the ancestors of fungus-growing ants began growing <a href="https://doi.org/10.1093/isd/ixab029">some 55 million to 65 million years ago</a>. Some of these fungi became domesticated and are now unable to survive on their own without their insect farmers, much like some human crops such as maize.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/-XuPtW8lBCM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Ants started farming tens of millions of years before humans.</span></figcaption>
</figure>
<p>Ant farmers face many of the same challenges human farmers do, including the threat of pests. A parasite called <a href="https://doi.org/10.1186/s43008-021-00078-8"><em>Escovopsis</em></a> can devastate ant gardens, causing the ants to starve. Likewise in human agriculture, pest outbreaks have contributed to disasters like the <a href="https://evolution.berkeley.edu/the-relevance-of-evolution/agriculture/monoculture-and-the-irish-potato-famine-cases-of-missing-genetic-variation/">Irish Potato Famine</a>, the 1970 <a href="https://doi.org/10.1126/science.171.3976.1113">corn blight</a> and the <a href="https://theconversation.com/with-the-familiar-cavendish-banana-in-danger-can-science-help-it-survive-64206">current threat to bananas</a>.</p>
<p>Since the 1950s, human agriculture has become industrialized and relies on <a href="https://www.birmingham.ac.uk/research/quest/preserving-and-creating-culture/a-global-history-of-monoculture.aspx">monoculture</a>, or growing large amounts of the same variety of crop in a single place. Yet monoculture makes crops more vulnerable to pests because it is easier to destroy an entire field of genetically identical plants than a more diverse one.</p>
<p>Industrial agriculture has looked to chemical pesticides as a partial solution, turning agricultural pest management into a <a href="https://www.alliedmarketresearch.com/pest-control-market">billion-dollar industry</a>. The trouble with this approach is that pests can <a href="https://islandpress.org/books/chasing-red-queen">evolve new ways to get around pesticides</a> faster than researchers can develop more effective chemicals. It’s an arms race – and the pests have the upper hand.</p>
<p>Ants also <a href="https://mitpress.mit.edu/9780262543200/the-convergent-evolution-of-agriculture-in-humans-and-insects/">grow their crops in monoculture</a> and at a similar scale – after all, a leafcutter ant nest can be home to <a href="https://wwnorton.com/books/9780393338683">5 million ants</a>, all of which feed on the fungi in their underground gardens. They, too, use a pesticide to control <em>Escovopsis</em> and other pests. </p>
<p>Yet, their approach to pesticide use differs from humans’ in one important way. Ant pesticides are <a href="https://doi.org/10.1021/acscentsci.0c00978">produced by bacteria</a> they allow to grow in their nests, and in some cases even on their bodies. Keeping bacteria as a living culture allows the microbes to <a href="https://doi.org/10.1128/AEM.00178-21">adapt in real time</a> to evolutionary changes in the pests. In the arms race between pests and farmers, farming ants have discovered that live bacteria can serve as pharmaceutical factories that can keep up with ever-changing pests.</p>
<p>Whereas recent developments in agricultural pest management have focused on <a href="https://entomology.ca.uky.edu/ef130">genetically engineering</a> <a href="https://www.nature.com/scitable/knowledge/library/use-and-impact-of-bt-maize-46975413/">crop plants</a> to produce their own pesticides, the lesson from 55 million years of ant agriculture is to <a href="https://doi.org/10.3389/fsoil.2022.833181">leverage living microorganisms</a> to make <a href="https://doi.org/10.1007/978-981-16-4843-4_13">useful products</a>. Researchers are currently experimenting with <a href="https://link.springer.com/book/10.1007/978-981-10-0707-1">applying live bacteria to crop plants</a> to determine if they are effective at producing pesticides that can evolve in real time along with pests.</p>
<h2>Improving transportation</h2>
<p>Ants can also offer practical lessons in the realm of transportation.</p>
<p>Ants are notoriously good at quickly locating food, whether it’s a dead insect on a forest floor or some crumbs in your kitchen. They do this by leaving a <a href="https://doi.org/10.1111/j.1365-3032.2008.00658.x">trail of pheromones</a> – chemicals with a distinctive smell ants use to guide their nest mates to food. The shortest route to a destination will accumulate the most pheromone because more ants will have traveled back and forth along it in a given amount of time.</p>
<p>In the 1990s, computer scientists developed a <a href="https://www.sciencedirect.com/topics/engineering/ant-colony-optimization">class of algorithms</a> modeled after ant behavior that are very effective at finding the shortest path between two or more locations. Like with real ants, the shortest route to a destination will accumulate the most virtual pheromone because more virtual ants will have traveled along it in a given amount of time. Engineers have used this simple but effective approach to <a href="https://doi.org/10.1016/j.mcm.2010.04.021">design telecommunication networks</a> and <a href="https://doi.org/10.1007%2F978-3-030-50146-4_25">map delivery routes</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Leafcutter ants crowding a patch of dirt" src="https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494755/original/file-20221110-3879-61v327.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Thousands of ants can travel along the same path without causing traffic jams.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/close-up-of-plant-growing-on-field-royalty-free-image/764924521">Esteban Castao Solano/EyeEm via Getty Images</a></span>
</figcaption>
</figure>
<p>Not only are ants good at finding the shortest route from their nests to a source of food, thousands of ants are capable of traveling along these routes without causing traffic jams. I recently began collaborating with physicist <a href="https://scholar.google.com/citations?user=reX35vUAAAAJ&hl=es">Oscar Andrey Herrera-Sancho</a> to study how leafcutter ants maintain such a steady flow along their foraging paths without the slowdowns typical of crowded human sidewalks and highways.</p>
<p>We are <a href="http://solomon.rice.edu/2019/01/11/field-research-in-costa-rica/">using cameras to track</a> how each individual ant responds to artificial obstacles placed on their <a href="https://www.alexanderwild.com/Ants/Making-a-Living/The-Farming-Ants-Leafcutters/i-rWjNDhM/A">foraging trails</a>. Our hope is that by getting a better understanding of the rules ants use to respond to both obstacles and the movement of other ants, we can develop algorithms that can eventually help program self-driving cars that never get stuck in traffic.</p>
<h2>Look to the ant</h2>
<p>To be fair, there are plenty of ways ants are far from perfect role models. After all, some ant species are known for <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674241558">indiscriminate killing</a>, and others for <a href="https://theconversation.com/slave-ants-and-their-masters-are-locked-in-a-deadly-relationship-36737">enslaving babies</a>. </p>
<p>But the fact is that ants <a href="https://www.basicbooks.com/titles/mark-w-moffett/the-human-swarm/9781541617292/">remind us of ourselves</a> – or the way we might like to imagine ourselves – in many ways. They live in complex societies with <a href="https://doi.org/10.1007/s00265-015-2045-3">division of labor</a>. They <a href="https://www.simonandschuster.com/books/Ants-At-Work/Deborah-Gordon/9781451665703">cooperate to raise their young</a>. And they accomplish <a href="https://press.princeton.edu/books/hardcover/9780691179315/ant-architecture">remarkable engineering feats</a> – like building structures with air funnels that can house millions – all without blueprints or a leader. Did I mention their societies are <a href="https://www.press.jhu.edu/books/title/10551/secret-lives-ants">run entirely by females</a>?</p>
<p>There is still a lot to learn about ants. For example, researchers still don’t fully understand <a href="https://doi.org/10.1016/j.tree.2020.11.010">how an ant larva develops</a> into either a queen – a female with wings that can live for 20 years and lay millions of eggs – or a worker – a wingless, often sterile female that lives for less than a year and performs all the other jobs in the colony. What’s more, scientists are constantly discovering new species – <a href="https://www.antwiki.org/wiki/Taxa_Described_in_2021">167 new ant species</a> were described in 2021 alone, bringing the total to more than 15,980. </p>
<p>By considering ants and their many fascinating ways, there’s plenty of wisdom to be gained.</p><img src="https://counter.theconversation.com/content/188939/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Scott Solomon receives funding from the National Science Foundation and the Big Thicket Association. </span></em></p>Over hundreds of million years of evolution, ants have come up with some pretty smart solutions to problems of agriculture, navigation and architecture. People could learn a thing or two.Scott Solomon, Associate Teaching Professor of Ecology and Evolutionary Biology, Rice UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1908312022-09-19T20:15:27Z2022-09-19T20:15:27ZEarth harbours 20,000,000,000,000,000 ants – and they weigh more than wild birds and mammals combined<figure><img src="https://images.theconversation.com/files/485266/original/file-20220919-20-399kqy.jpg?ixlib=rb-1.1.0&rect=0%2C302%2C5607%2C2606&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock </span></span></figcaption></figure><p>Have you ever wondered exactly how many ants live on Earth? Possibly not, but it’s certainly a question we’ve asked ourselves. </p>
<p>Our <a href="https://www.pnas.org/cgi/doi/10.1073/pnas.2201550119">research</a> published today provides an approximate answer. We conservatively estimate our planet harbours about 20 quadrillion ants. That’s 20 thousand million millions, or in numerical form, 20,000,000,000,000,000 (20 with 15 zeroes).</p>
<p>We further estimate the world’s ants collectively constitute about 12 million tonnes of dry carbon. This exceeds the mass of all the world’s wild birds and wild mammals combined. It’s also equal to about one-fifth of the total weight of humans. </p>
<p>Eminent biologist Edward O. Wilson once said insects and other invertebrates are “the little things that run the world” – and he was right. Ants, in particular, are a crucial <a href="https://harvardforest.fas.harvard.edu/ants/ecological-importance">part</a> of nature. Among other roles, ants aerate the soil, disperse seeds, break down organic material, create habitat for other animals and form an important part of the food chain. </p>
<p>Estimating ant numbers and mass provides an important baseline from which to monitor ant populations amid worrying environmental changes.</p>
<figure class="align-center ">
<img alt="two ants carry a seed" src="https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485169/original/file-20220918-29066-y4whhk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Many ant species are important seed dispersers. Here, two worker Meranoplus ants carry a seed back to their nest.</span>
<span class="attribution"><span class="source">Francois Brassard</span></span>
</figcaption>
</figure>
<h2>Counting the world’s ants</h2>
<p>There are more than 15,700 named species and subspecies of ants, and many others not yet named by science. Ants’ high degree of social organisation has enabled them to colonise nearly all ecosystems and regions around the globe.</p>
<p>The astounding ubiquity of ants has prompted many naturalists to <a href="https://www.bbc.com/news/magazine-29281253">contemplate</a> their exact number on Earth. But these were basically educated guesses. Systematic, evidence-based estimates have been lacking.</p>
<p>Our research involved an analysis of 489 studies of ant populations conducted by fellow ant scientists from around the world. This included non-English literature, in languages such as Spanish, French, German, Russian, Mandarin and Portuguese. </p>
<p>The research spanned all continents and major habitats including forests, deserts, grasslands and cities. They used standardised methods for collecting and counting ants such as pitfall traps and leaf litter samples. As you can imagine, this is often tedious work.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/in-defence-of-ants-186220">In defence of ants</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="hand squeezes bottle of green liquid into hole in ground" src="https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485168/original/file-20220918-47262-2jp0ey.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A researcher installs a pitfall trap, a standard method for collecting ants that crawl across the ground surface.</span>
<span class="attribution"><span class="source">Francois Brassard</span></span>
</figcaption>
</figure>
<p>From all this, we estimate there are approximately 20 quadrillion ants on Earth. This figure, though conservative, is between two and 20 times higher than previous estimates. </p>
<p>Th previous figures employed a “top-down” approach by assuming ants comprise about 1% of the world’s estimated insect population. In contrast, our “bottom-up” estimate is more reliable because it uses data on ants observed directly in the field and makes fewer assumptions.</p>
<p>Our next step was to work out how much all these ants weigh. The mass of organisms is <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1711842115">typically measured</a> in terms of their carbon makeup. We estimated that 20 quadrillion average-sized ants corresponds to a dry weight or “biomass” of approximately 12 million tonnes of carbon. </p>
<p>This is more than the combined biomass of wild birds and mammals – and about 20% of total human biomass.</p>
<p>Carbon makes up <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1711842115">about half</a> the dry weight of an ant. If the weight of other bodily elements was included, the total mass of the world’s ants would be higher still. </p>
<p>We also found ants are distributed unevenly on Earth’s surface. They vary sixfold between habitats and generally peak in the tropics. This underscores the importance of tropical regions in maintaining healthy ant populations.</p>
<p>Ants were also particularly abundant in forests, and surprisingly, in arid regions. But they become less common in human-made habitats. </p>
<p>Our findings come with a few caveats. For example, the sampling locations in our dataset are unevenly distributed across geographic regions. And the vast majority of samples were collected from the ground layer, meaning we have very little information about ant numbers in trees or <a href="https://www.asianscientist.com/2017/07/features/aswp2017-subterranean-ants/">underground</a>. This means our findings are somewhat incomplete. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/where-are-all-the-ants-world-first-treasure-map-reveals-hotspots-for-rare-species-188092">Where are all the ants? World-first ‘treasure map’ reveals hotspots for rare species</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="thousands of ants form a line across a road" src="https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485220/original/file-20220919-53704-yd22vt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The new research found ants are distributed unevenly on Earth’s surface.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>We all need ants</h2>
<p>Ants also provide vital “ecosystem services” for humans. For instance, a recent study <a href="https://www.theguardian.com/environment/2022/aug/17/ants-can-beat-pesticides-helping-farmers-grow-healthy-crops-study-aoe">found</a> ants can be more effective than pesticides at helping farmers produce food. </p>
<p>Ants have also developed tight interactions with other organisms – and some species cannot survive without them. </p>
<p>For example, some birds rely on ants to <a href="https://beta.nsf.gov/news/birds-follow-army-ants-find-prey">flush out</a> their prey. And thousands of plant species either <a href="https://www.kew.org/read-and-watch/ants-and-plants-a-very-natural-love-story">feed or house ants</a> in exchange for protection, or dispersal of their seeds. And many ants are predators, helping to keep populations of other insects in check.</p>
<figure class="align-center ">
<img alt="ant carries prey in jaws" src="https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/485170/original/file-20220918-15948-of2myk.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A purple Rhytidoponera ant carries her prey between her jaws. Many ants serve as predators that help keep populations of other insects in check.</span>
<span class="attribution"><span class="source">Francois Brassard</span></span>
</figcaption>
</figure>
<p>Alarmingly, global insect numbers are <a href="https://theconversation.com/climate-change-triggering-global-collapse-in-insect-numbers-stressed-farmland-shows-63-decline-new-research-170738#:%7E:text=Throughout%20the%20world%2C%20our%20analysis,habitat%20has%20been%20largely%20preserved">declining</a> due to threats such as habitat destruction and fragmentation, chemical use, invasive species and climate change.</p>
<p>But data on insect biodiversity is alarmingly scarce. We hope our study provides a baseline for further research to help fill this gap.</p>
<p>It’s in humanity’s interest to monitor ant populations. Counting ants is not difficult, and citizen scientists from all over the world could help investigate how these important animals are faring at a time of great environmental change.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-tiny-ants-have-invaded-your-house-and-what-to-do-about-it-132092">Why tiny ants have invaded your house, and what to do about it</a>
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</em>
</p>
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<img src="https://counter.theconversation.com/content/190831/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Wong receives funding from the Forrest Research Foundation. </span></em></p><p class="fine-print"><em><span>Benoit Guénard is an Associate Professor at The University of Hong Kong (HKU). This study was supported thanks to funding from HKU, an Early Career Scheme of the Research Grant Council of Hong Kong (# ECS-27106417), and by National Geographic.</span></em></p><p class="fine-print"><em><span>Patrick Schultheiss is a Temporary Principal Investigator at the University of Würzburg in Germany. He currently receives funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - project no. 499479766. This study was further supported by a Division of Ecology and Biodiversity Postdoctoral Fellow Research Award from the University of Hong Kong.</span></em></p><p class="fine-print"><em><span>Sabine Nooten receives funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) — project No. 445715161</span></em></p><p class="fine-print"><em><span>François Brassard and Runxi Wang do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Invertebrates are “the little things that run the world”. So researchers decided to count all the ants on Earth, to help monitor how they’re coping with environmental challenges.Mark Wong, Forrest Fellow, The University of Western AustraliaBenoit Guénard, Associate professor, University of Hong KongFrançois Brassard, PhD candidate, Charles Darwin UniversityPatrick Schultheiss, Temporary Principal Investigator, Julius Maximilian University of WürzburgRunxi Wang, PhD candidate, University of Hong KongSabine Nooten, Temporary Principal Investigator, Julius Maximilian University of WürzburgLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1885592022-09-12T12:12:36Z2022-09-12T12:12:36ZHow do ants crawl on walls? A biologist explains their sticky, spiky, gravity-defying grip<figure><img src="https://images.theconversation.com/files/478784/original/file-20220811-23-w41scx.jpg?ixlib=rb-1.1.0&rect=0%2C6%2C2272%2C1693&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Walking vertically – or even upside down – is a piece of cake for ants.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/climbing-up-a-wall-royalty-free-image/175996454">pecchio/iStock via Getty Images Plus</a></span></figcaption></figure><figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281719/original/file-20190628-76743-26slbc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/us/topics/curious-kids-us-74795">Curious Kids</a> is a series for children of all ages. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskidsus@theconversation.com">curiouskidsus@theconversation.com</a>.</em></p>
<hr>
<blockquote>
<p><strong>How do ants crawl on walls? – Ethan, age 9, Dallas, Texas</strong></p>
</blockquote>
<hr>
<p>When I first started my job <a href="https://scholar.google.com/citations?user=hrO-baMAAAAJ&hl=en&oi=ao">as a biologist</a> at the University of South Florida, I drove my Jeep to a grassy field, dug up a mound of fire ants and shoveled it into a 5-gallon bucket. Immediately, thousands of ants swarmed out of the soil and up the walls of the bucket headed for freedom. Luckily I had a lid.</p>
<p>How do ants make climbing walls, ceilings and other surfaces look so easy? <a href="https://scholar.google.com/citations?hl=en&view_op=list_works&gmla=AJsN-F7sTTsnLhAu39Zwg-90iH0Hwx9849J-UEbRISOmCR2ouYfcOp2_o8P0yqau7y64vL6XeYU3LFJ-RpqacVDz2Q8Qln7xBQ&user=hrO-baMAAAAJ">I’ve been studying ants for 30 years</a>, and their climbing abilities never cease to amaze me. </p>
<p>Worker ants – <a href="https://theconversation.com/six-amazing-facts-you-need-to-know-about-ants-100478">who are all female</a> – have an impressive <a href="https://doi.org/10.1007/s00114-006-0194-y">toolbox of claws, spines, hairs</a> and sticky pads on their feet that enable them to scale almost any surface.</p>
<h2>Human hands vs. ant feet</h2>
<p>To understand ant feet, it helps to compare them with human hands. Your hand has one broad segment, the palm. Sprouting from your palm are four fingers and an opposable thumb. Each finger has three segments, while your thumb has only two segments. A hard nail grows from the tips of your fingers and thumb.</p>
<p>Humans have two hands – ants have six feet. Ant feet are similar to your hands but are more complex, with an additional set of weird-looking parts that enhance them. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A microscopic view of an ant's foot, with segments numbered. Labeled are claw, thick spine, thin spine and hairs." src="https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/479207/original/file-20220815-14662-uvsojl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A closeup view of one multisegmented ant foot. Each foot is lined with spiky tools that help grip almost any surface.</span>
<span class="attribution"><span class="source">Deby Cassill</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Ant feet have five jointed segments, with the end segment sporting a pair of claws. The claws are shaped like a cat’s and can grip irregularities on walls. Each foot segment also has thick and thin spines and hairs that provide additional traction by sticking into microscopic pits on textured surfaces like bark. Claws and spines have the added benefit of protecting ant feet from hot pavement and sharp objects, just as your feet are protected by shoes. </p>
<p>But the feature that truly separates human hands from ant feet are inflatable sticky pads, called arolia.</p>
<h2>Sticky feet</h2>
<p><a href="https://pubs.rsc.org/en/content/articlehtml/2011/sm/c1sm06269g">Arolia are located between the claws at the tip of every ant foot</a>. These balloonlike pads allow ants to defy gravity and crawl on ceilings or ultrahard surfaces like glass.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A microscopic view of a fire ant's foot. The end shows two retracted claws revealing an inflated pillow like structure." src="https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478782/original/file-20220811-27-lrnm6e.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Inflatable sticky pads bring the cling.</span>
<span class="attribution"><span class="source">Deby Cassill</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>When an ant walks up a wall or across a ceiling, gravity causes its claws to swing wide and pull back. At the same time, its leg muscles pump fluids into the pads at the end of its feet, causing them to inflate. This <a href="https://bugunderglass.com/do-insects-have-blood/">body fluid is called hemolymph</a>, which is a sticky fluid similar to your blood that circulates throughout an ant’s body. </p>
<p>After the hemolymph pumps up the pad, some of it leaks outside the pad, which is how ants can stick to a wall or a ceiling. But when an ant picks up its foot, its leg muscles contract and suck most of the fluid back into the pad and then back up the leg. This way an ant’s blood is reused over and over – pumped from the leg into the pad, then sucked back up the leg – so none is left behind. </p>
<figure>
<img src="https://cdn.theconversation.com/static_files/files/2250/ezgif.com-gif-maker.gif?1660317974">
<figcaption><span class="Ant feet in action on glass. Courtesy of Deby Cassill.">Ant feet in action on glass. Courtesy of Deby Cassill.</span></figcaption>
</figure>
<p>Ants are feather-light, so six sticky pads are enough to hold them against the pull of gravity on any surface. In fact, at home in their underground chambers, <a href="https://doi.org/10.1007/s00114-006-0194-y">ants use their sticky pads to sleep on the ceiling</a>. By sleeping on the ceiling, ants avoid the rush-hour traffic of other ants on the chamber floors.</p>
<h2>A unique gait</h2>
<p>When you walk, your left and right feet alternate so one is on the ground while the other is in the air, moving forward. Ants also alternate their feet, with three on the surface and three in the air at a time. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/lduoLbm0_IU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A computer simulation showing an ant’s special walk. Created by Shihui Guo.</span></figcaption>
</figure>
<p>The walking pattern of ants is <a href="https://doi.org/10.1242/jeb.156.1.215">unique among six-legged insects</a>. In ants, the front and back left feet are on the ground with the middle right foot, while the front and back right feet and the middle left foot are in the air. Then they switch. It’s fun to try to copy this triangular pattern using three fingers on each hand. </p>
<p>The next time you see an ant crawling up a wall, look closely and you might witness some of these fascinating features at work.</p>
<hr>
<p><em>Hello, curious kids! Do you have a question you’d like an expert to answer? Ask an adult to send your question to <a href="mailto:curiouskidsus@theconversation.com">CuriousKidsUS@theconversation.com</a>. Please tell us your name, age and the city where you live.</em></p>
<p><em>And since curiosity has no age limit – adults, let us know what you’re wondering, too. We won’t be able to answer every question, but we will do our best.</em></p><img src="https://counter.theconversation.com/content/188559/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deby Cassill does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Ant feet are equipped with an array of tools – from retractable sticky pads to claws to special spines and hairs – enabling them to defy gravity and grip virtually any surface.Deby Cassill, Associate Professor of Integrative Biology, University of South FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1880922022-08-03T20:04:11Z2022-08-03T20:04:11ZWhere are all the ants? World-first ‘treasure map’ reveals hotspots for rare species<figure><img src="https://images.theconversation.com/files/477308/original/file-20220803-14-qtymxo.jpg?ixlib=rb-1.1.0&rect=20%2C0%2C3464%2C2320&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Ajay Narendra</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The American biologist E.O. Wilson famously called invertebrates “the little things that run the world”. Despite their great importance, we still know very little about the worms, insects and other small creatures that make up the majority of animal species. </p>
<p>Working with researchers from around the world, we have made an important step to improve this knowledge: a high-resolution map of ant species across the globe. </p>
<p>Published today in <a href="https://doi.org/10.1126/sciadv.abp9908">Science Advances</a>, this world-first map of ant diversity also acts as a “treasure map”, highlighting likely regions rich in undiscovered species.</p>
<h2>A big part of our world</h2>
<p>Invertebrates constitute the majority of animal species and are critical for ecosystem functioning and services. Nonetheless, global invertebrate biodiversity patterns and how they relate to vertebrate biodiversity remain largely unknown.</p>
<p>Like other invertebrates, ants are important for the functioning of ecosystems. They aerate soil, disperse seeds and nutrients, scavenge, and prey on other species. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477328/original/file-20220803-1926-f1t6qf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ants comprise a significant fraction of the animal biomass in most terrestrial ecosystems.</span>
<span class="attribution"><a class="source" href="https://unsplash.com/photos/L-1hBbNj4Ug">Prince Patel / Unsplash</a></span>
</figcaption>
</figure>
<p>Ants are hunters, farmers, harvesters, gliders, herders, weavers and carpenters. They are a big part of our world: there are more than 14,000 known species of ants, and they comprise a significant fraction of the animal biomass in most terrestrial ecosystems. </p>
<p>They are globally widespread and abundant, and their known species’ richness is comparable to birds and mammals combined. Yet we still lack a global view of their biodiversity. </p>
<h2>World-first high-resolution global diversity map of ants</h2>
<p>We used existing knowledge about biodiversity along with range modelling and machine learning to create a high-resolution (~20 km) map of the global diversity of ants and predict where undiscovered diversity is likely to exist.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=407&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=407&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=407&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=511&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=511&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477319/original/file-20220803-24-6ql8mv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=511&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mapping the diversity of ant species alongside diversity of vertebrates can help to discover and conserve precious ants.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1126/sciadv.abp9908">Kass et al., Sci Adv (2021)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Biodiversity among ants and other invertebrates is still poorly understood. We do not have good answers to basic questions such as which areas have the most species, which areas harbour concentrations of highly localised species, and even whether a major global decline in insect biomass is under way.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-is-killing-off-earths-little-creatures-109719">Climate change is killing off Earth’s little creatures</a>
</strong>
</em>
</p>
<hr>
<p>Through our research we found that, while the richness and rarity patterns of ants and vertebrate groups can show congruence, each has distinct features. This finding underscores the need to consider a diversity of taxa in conservation.</p>
<h2>The research</h2>
<p>This project began a decade ago with Benoit Guénard (then at the Okinawa Institute of Science and Technology, now at the University of Hong Kong) and Evan Economo (currently at Harvard). They set out to create a database of occurrence records for different ant species from online repositories, museum collections and around 10,000 scientific publications. </p>
<p>Researchers around the world contributed and helped identify errors. More than 14,000 species were considered.</p>
<p>However, the vast majority of these records, while containing a description of the sampled location, did not have the precise co-ordinates needed for mapping. To address this, Kenneth Dudley from the <a href="https://groups.oist.jp/edss">Environmental Informatics Section</a> at the Okinawa Institute of Science and Technology created a way to estimate the co-ordinates from the available data and also check the data for errors.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the world with some areas shaded." src="https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=288&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=288&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=288&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=362&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=362&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477312/original/file-20220803-19-xnc0jr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=362&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The top 10% of areas for rare ant species around the world. Areas shaded with diagonal lines are also centres of rare vertebrates.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1126/sciadv.abp9908">Kass et al., Sci Adv (2021)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Then Jamie Kass and research technician Fumika Azuma, also at at the Okinawa Institute of Science and Technology, made different range estimates for each species of ant depending on how much data was available. </p>
<p>For species with less data, they constructed shapes surrounding the data points. For species with more data, the researchers predicted the distribution of each species using statistical models.</p>
<p>The researchers brought these estimates together to form a global map, divided into a grid of 20km by 20km squares. It shows an estimate of the number of ant species living in each square (called the species richness). </p>
<p>They also created a map showing the number of ant species with very small ranges in each square (called the species rarity). In general, species with small ranges are particularly vulnerable to environmental changes.</p>
<h2>Unsampled territory</h2>
<p>However, there was another problem to overcome: sampling bias.</p>
<p>Some parts of the world that we expected to have high levels of diversity were not showing up on our map, but ants in these regions were not well studied.</p>
<p>Other areas were extremely well sampled, for example, parts of the USA and Europe. This difference in sampling can impact our estimates of global diversity.</p>
<p>So, we used machine learning to predict how the diversity would change if we sampled all areas around the world equally. In this process, we identified areas where we think many unknown, unsampled species exist.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/climate-change-triggering-global-collapse-in-insect-numbers-stressed-farmland-shows-63-decline-new-research-170738">Climate change triggering global collapse in insect numbers: stressed farmland shows 63% decline – new research</a>
</strong>
</em>
</p>
<hr>
<p>This gives us a kind of “treasure map”, which can guide us to where we should explore next and look for new species with restricted ranges. Within Australia, high levels of ant biodiversity are found along the east, north-western and south-western coasts.</p>
<p>Finally, we looked at how well-protected these areas of high ant diversity are.</p>
<p>We found it was a low percentage – only 15% of the top 10% of ant rarity centres had some sort of legal protection, such as a national park or reserve, which is less than existing protection for vertebrates.</p>
<p>Clearly, we have a lot of work to do to protect these critical areas.</p><img src="https://counter.theconversation.com/content/188092/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Robson receives funding from The Australian Research Council. </span></em></p>A new map of more than 14,000 ant species around the world will guide efforts for discovery and conservation.Simon KA Robson, Professor, CQUniversity AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1862202022-07-14T15:40:26Z2022-07-14T15:40:26ZIn defence of ants<figure><img src="https://images.theconversation.com/files/473382/original/file-20220711-16-4u9rtu.jpg?ixlib=rb-1.1.0&rect=200%2C0%2C4401%2C2117&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Common black ant.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/common-black-ant-garden-selective-focus-1765508066">Shutterstock</a></span></figcaption></figure><p>To the uninitiated there are two types of ants in the UK: the red ones that bite and black ants which invade our kitchens. Even more alarming is when hundreds of local ant colonies swarm and create a regional “<a href="https://www.nhm.ac.uk/discover/when-why-winged-ants-swarm-nuptial-flight.html">flying ant day</a>”.</p>
<p>People can develop an intense fear of ants called <a href="https://www.fearof.net/fear-of-ants-phobia-myrmecophobia">myrmecophobia</a>. Although this is more likely to happen if they are allergic to ant bites and stings. </p>
<p>The ant scuttling across my kitchen floor this morning would, to most people, simply be a black ant and a nuisance, but it’s my favourite species. Small, with a short waist between thorax and abdomen, I identified it as <em>Lasius niger</em> (the black garden ant). This is Britain’s most common ant species, just one of 51 that <a href="https://www.antnest.co.uk/ant-species-uk">live in the UK</a>, plus 13 introduced species. </p>
<p>Worldwide there are about <a href="https://animal-knowledge.com/category/insects/ants/">16,000 ant species</a> in colonies of up to 500,000 individuals. They can all bite (though most are too small to hurt) some sting, and all produce <a href="https://owlcation.com/stem/Formic-Acid-Dangers-and-Uses-in-Nature-and-in-Humans">formic acid</a> for protection and attack. That all sounds a bit worrying if you’re not an insect person. </p>
<h2>What use are ants?</h2>
<p>Anyone who has been bitten by an ant may wonder what the point of the bothersome little creatures is. But the truth is we simply couldn’t do without them. </p>
<p>Ants help to break down organic matter. Without them it would accumulate, reducing soil quality. Studies on <a href="https://besjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1365-2664.12496">weaver ants</a> <em>Oecophylla smaragdina</em> demonstrate they reduce pests and can improve crop yield. <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/weaver-ant">Some people eat</a> weaver ants as they are high in protein and fatty acids. </p>
<p>Ants tunnel and build underground nests. As ecosystem engineers they <a href="https://www.researchgate.net/publication/228499939">improve soil porosity</a> to air and water, increasing pH and vital soil nutrients. The wildlife we love to watch from our gardens or in nature reserves depends on ants. They are eaten by <a href="https://www.woodlandtrust.org.uk/trees-woods-and-wildlife/animals/birds/green-woodpecker/">green woodpeckers</a>, for example. Larvae of the endangered <a href="https://butterfly-conservation.org/butterflies/large-blue">large blue butterfly</a> also feed on red ant larvae. </p>
<p>All ants live in a highly structured community. They share information and <a href="https://phys.org/news/2015-08-ants-complex-societies.html">collectively make decisions</a>. Most ants are workers, produced from fertilised eggs. They have different roles <a href="https://journals.biologists.com/jeb/article/220/1/53/33443/Caste-development-and-evolution-in-ants-it-s-all">according to age</a>; deep in the nest caring for larvae when young, then cleaning and transporting food, and finally scouting and collecting food when older (and more dispensible). Some tropical ant species have soldiers for defence and attack, which like workers are all female. UK wood ants (<em>Formica rufa</em>) don’t have soldiers so workers take on the role. <em>Formica sanguinea</em> raid colonies of <em>Formica fusca</em> and take larvae that grow up to become their slaves.</p>
<p>Some species such as <em>Lasius niger</em> establish themselves in houses, and I tracked my ant to a colony that was hollowing out the pantry wall (now repaired). Not harmful to humans in itself, each <em>L. niger</em> has a specific job, and mine was a scout. It would return a food sample <a href="https://link.springer.com/article/10.1007/s10164-016-0494-4">to the colony</a>. Other ants would follow the <a href="https://www.livescience.com/495-ants-navigate.html">scout ant</a> to the food source. <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/lasius-niger"><em>L niger</em> </a> scouts lay chemical trails to bring its sisters to food. </p>
<p>When the colony becomes too large, the queen produces winged ants. They are fertile princesses which develop from fertilised eggs, and males from <a href="https://theconversation.com/six-amazing-facts-you-need-to-know-about-ants-100478">unfertilised eggs</a>. Swarms are triggered by warm, humid conditions after rain. Flying ants use their wings only once. </p>
<p>Swarming encourages genetic mixing as males from other nests chase each princess. The males then die from <a href="https://antsauthority.com/why-do-male-ants-die-after-mating">exhaustion and damage</a> inflicted during mating. New queens shed their wings and start a nest of female workers. The old queen stays and can live for 25 years. All her young come from one nuptial flight, though she may mate with several males.</p>
<h2>Not all red ants sting</h2>
<p>Another common species is <em>Myrmica rubra</em>, a red ant sometimes called the European fire ant. Common across the UK and Europe, it has invaded <a href="https://link.springer.com/article/10.1007/s00040-018-0612-0">North America and Asia</a>. <em>M. rubra</em> is aggressive and if provoked, it bites and often stings. <em>M. rubra</em> forms mounds or lives under stones in grassland or sand dunes. As it searches for food it can disrupt a picnic, but it rarely ventures indoors. A lot of people think of red ants as bad ants. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/473383/original/file-20220711-14-zvyojp.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fire ant.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/fire-ant-on-branch-nature-green-1084620884">Shutterstock</a></span>
</figcaption>
</figure>
<p>One study investigated the <a href="https://www.academia.edu/48212447">differences in behaviour</a> of both species by providing them, one at a time, with a route to a container of springtails (tiny wingless insects eaten by ants).</p>
<p>Although <em>M. rubra</em> on average spent a third less time in the chamber than <em>L. niger</em>, it made three times as many aggressive contacts with the springtails, and killed almost seven times as many. So, <em>M. rubra</em> is more predatory, but living in exposed places is at a greater risk of attack. You can hardly blame it for defending itself. <em>L. niger</em> is too small to inflict a painful bite and has no sting. </p>
<p>Most ants don’t harm us, unless we threaten them. Although they can damage crops. Red ants, for instance, could destroy your allotment (they keep aphids as pets to feed on their sugary secretions).</p>
<p>So they may <a href="https://onebyoneantsmarch.weebly.com/humans-and-ants.html">invade your house</a>, steal your food and damage your vegetable patch. But the majority of British ants lead blameless lives underground as architects of soil health in complex societies.</p><img src="https://counter.theconversation.com/content/186220/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher Terrell Nield does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Give ants a chance.Christopher Terrell Nield, Principal lecturer, bioscience, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1500452021-12-27T13:57:23Z2021-12-27T13:57:23ZE.O. Wilson’s lifelong passion for ants helped him teach humans about how to live sustainably with nature<figure><img src="https://images.theconversation.com/files/384069/original/file-20210212-19-p6yza6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4874%2C3261&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Edward O. Wilson in his office in the Museum of Comparative Zoology at Harvard, in 2014.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/biologist-naturalist-and-writer-e-o-wilson-in-his-harvard-news-photo/454335232?adppopup=true">Suzanne Kreiter/The Boston Globe via Getty Images</a></span></figcaption></figure><p>E. O. Wilson was an extraordinary scholar in every sense of the word. Back in the 1980s, Milton Stetson, the chair of the biology department at the University of Delaware, told me that a scientist who makes a single seminal contribution to his or her field has been a success. By the time I met <a href="https://eowilsonfoundation.org/e-o-wilson/">Edward O. Wilson</a> in 1982, he had already made at least five such contributions to science.</p>
<p>Wilson, <a href="https://www.nytimes.com/2021/12/27/science/eo-wilson-dead.html">who died Dec. 26, 2021 at the age of 92</a>, discovered the <a href="https://doi.org/10.1016/0003-3472(62)90143-4">chemical means by which ants communicate</a>. He worked out the importance of habitat size and position within the landscape in <a href="https://press.princeton.edu/books/paperback/9780691088365/the-theory-of-island-biogeography">sustaining animal populations</a>. And he was the first to understand the evolutionary basis of <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674002357">both animal and human societies</a>.</p>
<p>Each of his seminal contributions fundamentally changed the way scientists approached these disciplines, and explained why E.O. – as he was fondly known – was an academic god for many young scientists like me. This astonishing record of achievement may have been due to his phenomenal ability to piece together new ideas using information garnered from disparate fields of study. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/knLdKcx6VXk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">E.O. Wilson reflects on insect society, human society and the importance of biodiversity in 2009.</span></figcaption>
</figure>
<h2>Big insights from small subjects</h2>
<p>In 1982 I cautiously sat down next to the great man during a break at a small conference on social insects. He turned, extended his hand and said, “Hi, I’m Ed Wilson. I don’t believe we’ve met.” Then we talked until it was time to get back to business. </p>
<p>Three hours later I approached him again, this time without trepidation because surely now we were the best of friends. He turned, extended his hand, and said “Hi, I’m Ed Wilson. I don’t believe we’ve met.” </p>
<p>Wilson forgetting me, but remaining kind and interested anyway, showed that beneath his many layers of brilliance was a real person and a compassionate one. I was fresh out of graduate school, and doubt that another person at that conference knew less than I — something I’m sure Wilson discovered as soon as I opened my mouth. Yet he didn’t hesitate to extend himself to me, not once but twice.</p>
<p>Thirty-two years later, in 2014, we met again. I had been invited to speak in a ceremony honoring his receipt of the Franklin Institute’s Benjamin Franklin Medal for Earth and Environmental Science. The award honored Wilson’s lifetime achievements in science, but particularly his many efforts to <a href="https://www.half-earthproject.org/">save life on Earth</a>.</p>
<p>My work <a href="https://scholar.google.com/citations?user=-vJ6qgkAAAAJ&hl=en">studying native plants and insects</a>, and how crucial they are to food webs, was inspired by Wilson’s eloquent descriptions of biodiversity and how the myriad interactions among species create the conditions that enable the very existence of such species. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&rect=46%2C23%2C3619%2C2533&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/384067/original/file-20210212-13-tjzzd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Biologist E.O. Wilson with models of his life’s greatest subject, ants.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/harvard-university-professor-e-o-wilson-in-his-office-at-news-photo/593351174?adppopup=true">Rick Friedman/Corbis via Getty Images</a></span>
</figcaption>
</figure>
<p>I spent the first decades of my career studying the evolution of insect parental care, and Wilson’s early writings provided a number of testable hypotheses that guided that research. But his 1992 book, “<a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674058170">The Diversity of Life</a>,” resonated deeply with me and became the basis for an eventual turn in my career path.</p>
<p>Though I am an entomologist, I did not realize that insects were “<a href="https://doi.org/10.1111/j.1523-1739.1987.tb00055.x">the little things that run the world</a>” until Wilson explained why this is so in 1987. Like nearly all scientists and nonscientists alike, my understanding of how biodiversity sustains humans was embarrassingly cursory. Fortunately, Wilson opened our eyes.</p>
<p>Throughout his career Wilson flatly rejected the notion held by many scholars that natural history – the study of the natural world through observation rather than experimentation – was unimportant. He proudly <a href="https://islandpress.org/books/naturalist-25th-anniversary-edition">labeled himself a naturalist</a>, and communicated the urgent need to study and preserve the natural world. Decades before it was in vogue, he recognized that our refusal to acknowledge the Earth’s limits, coupled with the unsustainability of perpetual economic growth, had set humans well on their way to ecological oblivion. </p>
<p>Wilson understood that humans’ reckless treatment of the ecosystems that support us was not only a recipe for our own demise. It was forcing the biodiversity he so cherished into the <a href="https://www.nytimes.com/2016/03/13/opinion/sunday/the-global-solution-to-extinction.html?_r=3">sixth mass extinction</a> in Earth’s history, and the first one caused by an animal: us. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Color-coded map of forest losses." src="https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=356&fit=crop&dpr=1 600w, https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=356&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=356&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=447&fit=crop&dpr=1 754w, https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=447&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/386572/original/file-20210225-13-ssa31h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=447&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">E.O. Wilson long advocated conserving the world’s biodiversity hot spots – zones with high numbers of native species where habitats are most endangered. This image shows deforestation from 1975 to 2013 in one such area, West Africa’s Upper Guinean Forest.</span>
<span class="attribution"><a class="source" href="https://eros.usgs.gov/westafrica/land-cover/deforestation-upper-guinean-forest">USGS</a></span>
</figcaption>
</figure>
<h2>A broad vision for conservation</h2>
<p>And so, to his <a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674040755">lifelong fascination with ants</a>, E. O. Wilson added a second passion: guiding humanity toward a more sustainable existence. To do that, he knew he had to reach beyond the towers of academia and write for the public, and that one book would not suffice. Learning requires repeated exposure, and that is what Wilson delivered in “The Diversity of Life,” “<a href="https://www.hup.harvard.edu/catalog.php?isbn=9780674074422&content=reviews">Biophilia</a>,” “<a href="https://www.penguinrandomhouse.com/books/191845/the-future-of-life-by-edward-o-wilson/">The Future of Life</a>,” “<a href="https://wwnorton.com/books/9780393330489">The Creation</a>” and his final plea in 2016, “<a href="https://wwnorton.com/books/9781631492525">Half-Earth: Our Planet’s Fight for Life</a>.”</p>
<p>As Wilson aged, desperation and urgency replaced political correctness in his writings. He boldly exposed ecological destruction caused by fundamentalist religions and unrestricted population growth, and challenged the central dogma of conservation biology, demonstrating that conservation could not succeed if restricted to tiny, isolated habitat patches. </p>
<p>In “Half Earth,” he distilled a lifetime of ecological knowledge into one simple tenet: Life as we know it can be sustained only if we preserve functioning ecosystems on at least half of planet Earth.</p>
<p>But is this possible? Nearly half of the planet is used for some form of agriculture, and 7.9 billion people and their vast network of infrastructure occupy the other half.</p>
<p>As I see it, the only way to realize E.O.’s lifelong wish is learn to <a href="https://www.workman.com/products/natures-best-hope">coexist with nature</a>, in the same place, at the same time. It is essential to bury forever the notion that humans are here and nature is someplace else. Providing a <a href="https://www.workman.com/products/bringing-nature-home">blueprint for this radical cultural transformation</a> has been my goal for the last 20 years, and I am honored that it melds with E.O. Wilson’s dream. </p>
<p>There is no time to waste in this effort. Wilson himself once said, “Conservation is a discipline with a deadline.” Whether humans have the wisdom to meet that deadline remains to be seen.</p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://memberservices.theconversation.com/newsletters/?nl=science&source=inline-science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/150045/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Doug Tallamy received funding from NSF 2015 for research on Chickadees. </span></em></p>E.O. Wilson was one of the world’s leading experts on ants, but his other passion was convincing humans to see themselves as part of the natural world.Doug Tallamy, Professor of Entomology, University of DelawareLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1737122021-12-20T14:17:10Z2021-12-20T14:17:10ZCurious Kids: how are ants and other creatures able to walk on the ceiling?<figure><img src="https://images.theconversation.com/files/438412/original/file-20211220-19-1ysfzvb.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2783%2C1849&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/black-ants-on-white-background-looks-1658247745">Local culture in northern/Shutterstock</a></span></figcaption></figure><p><strong>Why doesn’t gravity bother ants and other creatures that can climb up walls or walk along ceilings? – Tsubamé, aged eight, London, UK</strong></p>
<p>The reason most animals are not able to walk on the ceiling is due to a force called <a href="https://www.coolkidfacts.com/gravity/">gravity</a>. Gravity pulls everything down to the Earth. So, when you jump up, you are pulled back down. </p>
<p>This force will try to pull us down if we are dangling from something, so we need to have a strong hold if we are to hang from anything without falling off.</p>
<p>Now, although walls and ceilings look really smooth to us, they are in fact covered in lots of tiny holes and gaps. Small animals such as ants or spiders have very small feet, and they often have hundreds of thousands of <a href="https://theconversation.com/curious-kids-why-do-spiders-have-hairy-legs-108602">hairs and bristles</a> on their legs and feet. </p>
<p>These hairs and bristles can fit into the holes and gaps on walls. The ceilings are a bit like climbing walls for the insects – they can grab hold of lumps and bumps, using their many hairs, and stay put.</p>
<h2>Hold on tight</h2>
<p>There’s more to it than that, though. Insects attach to ceilings using something called a “<a href="https://kids.kiddle.co/Van_der_Waals_force">van der Waals force</a>”. This is when tiny molecules, such as those in the microscopic hairs on the end of insect’s feet, press really close to other molecules and stick together. </p>
<hr>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=293&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=293&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=293&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=368&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=368&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282267/original/file-20190702-126345-1np1y7m.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=368&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption"></span>
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<p><em><a href="https://theconversation.com/au/topics/curious-kids-36782">Curious Kids</a> is a series by <a href="https://theconversation.com/uk">The Conversation</a> that gives children the chance to have their questions about the world answered by experts. If you have a question you’d like an expert to answer, send it to <a href="mailto:curiouskids@theconversation.com">curiouskids@theconversation.com</a> and make sure you include the asker’s first name, age and town or city. We won’t be able to answer every question, but we’ll do our very best.</em></p>
<hr>
<p>If we were to put our feet on a wall, there would always be small gaps between us and the wall, so we wouldn’t be able to stick. However, if a tiny insect, with even tinier feet, were to push its hairs against a wall, the molecules in the hairs can stick to the molecules on the wall. </p>
<p>The stickiness is weak, but with enough hairs sticking to the wall it is enough to keep the insects on the ceiling. As the sticking occurs because of a molecular force, this means that the insects can stick to a surface whether it is wet or dry, and they can even stick to very smooth surfaces such as glass.</p>
<p>Also, these animals are all very small and light. Lighter animals have a lower gravitational force acting on them to pull them off the ceiling. The stickiness of the van der Waals force is more powerful than the forces of gravity, so the insect sticks.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close up image of hairy insect foot" src="https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=426&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=426&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=426&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=536&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=536&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438409/original/file-20211220-19-gogiv4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=536&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Hairs on a weevil’s foot help it stick to surfaces.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/131104726@N02/17867397875/in/photostream/">Todd Olson - University of Texas/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The hairs and bristles on insects’ feet increase the surface area, giving the insect a larger foot to stick to the ceiling. This makes insects really good at holding on. </p>
<h2>Stuck like glue</h2>
<p>Some insects are also able to produce a sticky substance, made from sugars and oils, from the end of each of their hairs. This acts a bit like glue, giving them even better sticking power to stay on walls and ceilings. In fact, if you look really closely where a fly has walked, you might see tiny, <a href="https://www.livescience.com/10536-flies-walk-ceilings.html">greasy footprints</a> from the sticky glue.</p>
<p>Most insects also have claws at the end of their legs. Although these claws help them to hold on to things, the claws stop the insects from becoming stuck to surfaces forever. When the insect pushes down with its claw, it also twists it a bit to release the foot from the surface, allowing them to walk around.</p>
<p>It’s not just insects that can walk on walls and ceilings. Some reptiles and amphibians such as geckos and tree frogs can “stick” to ceilings. This is usually due to the same principles: huge toes to increase the sticking area, lots of small hairs and a secretion of gluey mucous.</p><img src="https://counter.theconversation.com/content/173712/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Louise Gentle works for Nottingham Trent University. </span></em></p>A clue is in insects’ hairy feet.Louise Gentle, Senior Lecturer in Wildlife Conservation, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1644802021-09-01T12:10:13Z2021-09-01T12:10:13ZZinc-infused proteins are the secret that allows scorpions, spiders and ants to puncture tough skin<figure><img src="https://images.theconversation.com/files/415978/original/file-20210813-18-7h8fku.jpg?ixlib=rb-1.1.0&rect=52%2C0%2C3122%2C1547&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A close-up of the head of a leafcutter ant, Atta cephalotes, showing the metal-infused teeth on its mandibles.</span> <span class="attribution"><span class="source">Ryan Garrett</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p>
<h2>The big idea</h2>
<p>Many small animals grow their teeth, claws and other “tools” out of materials that are filled with zinc, <a href="https://doi.org/10.1016/j.jsb.2009.01.007">bromine</a> and manganese, reaching up to 20% of the material’s weight. My colleagues and I call these “heavy element biomaterials,” and in a <a href="https://www.nature.com/articles/s41598-021-91795-y">new paper</a>, we suggest that these materials make it possible for animals to grow scalpel-sharp and precisely shaped tools that are resistant to breaking, deformation and wear. </p>
<p>Because of the small size of things like ant teeth, it has been hard for biologists to test how well the materials they are made of resist fractures, impacts and abrasions. My research group <a href="https://www.nature.com/articles/s41598-021-91795-y">developed machines and methods to test these and other properties</a>, and along with our collaborators, we <a href="https://www.nature.com/articles/s41598-021-91795-y">studied their composition and molecular structure</a>. </p>
<p>We examined ant mandible teeth and found that they are a <a href="https://www.nature.com/articles/s41598-021-91795-y">smooth mix of proteins and zinc</a>, with single zinc atoms attached to about a quarter of the amino acid units that make up the proteins forming the teeth. In contrast, calcified tools – like human teeth – are made of <a href="https://darkwing.uoregon.edu/%7Ermss/HomogeneousAlternativeOutreach21-7-25.pdf">relatively large chunks of calcium minerals</a>. We think the lack of chunkiness in heavy element biomaterials makes them better than calcified materials at forming smooth, precisely shaped and extremely sharp tools. </p>
<p>To evaluate the advantages of heavy element biomaterials, we estimated the force, energy and muscle size required for cutting with tools made of different materials. Compared with other hard materials grown by these animals, the wear-resistant zinc material enables heavily used tools to puncture stiff substances using only one-fifth of the force. The estimated advantage is even greater relative to calcified materials that – since they can’t be nearly as sharp as heavy element biomaterials - can require more than 100 times as much force. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Images of heavy elements in ant, worm, scorpion and spider 'tools' above photos of the same things" src="https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=215&fit=crop&dpr=1 600w, https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=215&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=215&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=270&fit=crop&dpr=1 754w, https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=270&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/417913/original/file-20210825-18027-13u80cy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=270&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Biomaterials that incorporate zinc (red) and manganese (orange) are located in the important cutting and piercing edges of ant mandibles, worm jaws and other ‘tools.’</span>
<span class="attribution"><span class="source">Robert Schofield</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Why it matters</h2>
<p>It’s not surprising that materials that could make sharp tools would evolve in small animals. A tick and a wolf both need to puncture the same elk skin, but the wolf has vastly stronger muscles. The tick can make up for its tiny muscles by using <a href="https://doi.org/10.1098/rsfs.2016.0002">sharper tools that focus force onto smaller regions</a>. </p>
<p>But, like a sharp pencil tip, <a href="https://doi.org/10.1098/rsfs.2016.0002">sharper tool tips break more easily</a>. The danger of fracture is made even worse by the tendency for small animals to <a href="https://doi.org/10.1098/rsfs.2016.0002">extend their reach using long thin tools</a> – like those pictured above. And a chipped claw or tooth may be fatal for a small animal that doesn’t have the strength to cut with blunted tools.</p>
<p>But we found that heavy element biomaterials are also particularly <a href="https://www.nature.com/articles/s41598-021-91795-y">hard and damage-resistant</a>.</p>
<p>From an evolutionary perspective, these materials allow smaller animals to consume tougher foods. And the energy saved by using less force during cutting can be important for any animal. These advantages may explain <a href="https://www.nature.com/articles/s41598-021-91795-y">the widespread use of heavy element biomaterials in nature</a> – most ants, many other insects, spiders and their relatives, marine worms, crustaceans and many other types of organisms use them.</p>
<h2>What still isn’t known</h2>
<p>While my team’s research has clarified the advantages of heavy element biomaterials, we still don’t know exactly how zinc and manganese harden and protect the tools. </p>
<p>One possibility is that a small fraction of the zinc, for example, forms bridges between proteins, and these cross-links stiffen the material – like crossbeams stiffen a building. We also think that when a fang bangs into something hard, these zinc cross-links may break first, absorbing energy to keep the fang itself from chipping. </p>
<p>We speculate that the abundance of extra zinc is a ready supply for healing the material by quickly reestablishing the broken zinc-histidine cross-links between proteins.</p>
<h2>What’s next?</h2>
<p>The potential that these materials are self-healing makes them even more interesting, and our team’s next step is to test this hypothesis. Eventually we may find that self-healing or other features of heavy element biomaterials could lead to improved materials for things like small medical devices. </p>
<p>[<em>Over 110,000 readers rely on The Conversation’s newsletter to understand the world.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=100Ksignup">Sign up today</a>.]</p><img src="https://counter.theconversation.com/content/164480/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Robert Schofield received funding from the National Science Foundation, grants no. DMR-1408933 and DMR-2104177</span></em></p>Many small animals make their teeth and claws from a smooth blend of proteins and heavy elements. These materials can form very sharp tools that make it possible to cut tough substances using tiny muscles.Robert Schofield, Research Professor in Physics, University of OregonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1584262021-04-20T20:09:48Z2021-04-20T20:09:48ZTiny Game of Thrones: the workers of yellow crazy ants can act like lazy wannabe queens. So we watched them fight<figure><img src="https://images.theconversation.com/files/395945/original/file-20210420-19-1k7ptd6.png?ixlib=rb-1.1.0&rect=538%2C0%2C3455%2C2000&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Wes Mountain/The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>The invasive ant world is a competitive one, rife with territorial battles and colony raids. And yellow crazy ants (<em>Anoplolepis gracilipes</em>), one of the world’s <a href="http://www.iucngisd.org/gisd/100_worst.php">worst invasive species</a>, have an especially interesting trait: they’re the only invasive ant known to have <a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-017-0210-4">workers who can reproduce</a>.</p>
<p>Worker reproduction has <a href="https://www.journals.uchicago.edu/doi/10.1086/415930">big implications</a> for a colony’s social dynamic. So we observed and <a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00392-2">experimented with</a> more than 200 captive colonies of yellow crazy ants to understand what triggers worker reproduction and the potential costs and benefits for the colony. </p>
<p>We used a range of techniques, including removing queens and observing worker behaviour, and setting up ant gladiator rings to test how well reproductive workers fought other ants. </p>
<p>It wasn’t just for fun — learning about ants’ basic biology, including reproduction, may allow us to better understand their success and tailor management programs to <a href="https://www.environment.gov.au/system/files/resources/cd1170d3-7e62-4340-b0d1-c366e495e238/files/invasive-ant-biosecurity-2019.pdf">help save the ecosystems they threaten</a>.</p>
<h2>Life in the queendom</h2>
<p>Yellow crazy ants are thought to originate in southern or southeastern Asia but <a href="https://antmaps.org/?mode=species&species=Anoplolepis.gracilipes">have spread across</a> much of the Indo-Pacific, including several locations in Australia. They’re most well known for the cascade of <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1461-0248.2003.00512.x">ecological effects</a> they’ve caused on Christmas Island by killing red land crabs and contributing to the damage, such as tree die-back, caused by scale insects. </p>
<p><a href="https://www.wettropics.gov.au/our-battle-plan">Attempts to control or locally eradicate them</a> are ongoing on Christmas Island, in Arnhem Land, and several locations in Queensland, including in and around the Wet Tropics World Heritage Area.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/swAyy_jPD8o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Yellow crazy ants, accidentally introduced by cargo ships, and subsequently multiplying to number in the billions, threaten the yearly crab migration on Christmas Island.</span></figcaption>
</figure>
<p>Like honey bees and wasps, yellow crazy ants are social insects. In these colonies, queens, workers and males all play distinct roles.</p>
<p>Queens and workers are all females. The queens reproduce, while the aptly named workers are the colony’s labourers, primarily responsible for bringing in food, caring for the queens’ offspring and defending the colony. The sole role of males is to mate with a queen before dying. </p>
<p>This elaborate task division is thought key to the success of social insects. However, in yellow crazy ant colonies, workers challenge the reproductive monopoly of the queen and produce males. </p>
<p>We could differentiate workers with active ovaries from regular workers by looking at their abdomen, which would be oversized as eggs take up space in the larger workers’ abdomen.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Five yellow crazy ants, four of which have large abdomens" src="https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395413/original/file-20210416-15-1a9ng46.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In this picture, the worker ant on the far right has a regular-sized abdomen while the other workers have abdomen that looks swollen.</span>
<span class="attribution"><span class="source">Dr Peter Yeeles</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>When the queen was present, typically less than 20% of workers in our captive colonies had oversized abdomens. When we removed the queen, as much as half of the workers became oversized. We returned the queen after two months, and found the number of oversized workers decreased. </p>
<p>Our findings are consistent with the idea queens inhibit worker reproduction through pheromones, one of many chemical signals in ant colonies influencing ant worker behaviour and colony dynamics. Indeed, an ant queen’s failure to “smell” fertile may leave her <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/ece3.7173">subject to eviction or execution</a>.</p>
<h2>More lazy than crazy</h2>
<p>So, did our yellow crazy ant queen wannabes behave more like workers or royalty? <a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00392-2">Our observations</a> of oversized and normal workers revealed stark differences in behaviour. </p>
<p>Regular workers foraged during 85% of observations, whereas oversized workers were seen looking for food in only 5% of observations. Most of the time, oversized workers were immobile and remained sheltered inside their nests. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three yellow crazy ants" src="https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395931/original/file-20210420-17-dxcyuw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Regular-sized workers are territorial and aggressive.</span>
<span class="attribution"><span class="source">Peter Yeeles</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>These oversized workers are slow to move when the nests are disturbed, not displaying the fast, erratic movement for which the species is named. Their behaviour was more similar to queens than workers. </p>
<p>Colony and resource defence is another important task for workers, as yellow crazy ant colonies often compete with native ants.</p>
<p>To test how these sluggish workers compare to normal workers in colony defence, we placed three oversized workers in one container, three regular workers in another, and paired each group with one gladiator, the charismatic green tree ant. </p>
<p>Green tree ants (<em>Oecophylla smaragdina</em>) are native and known for being very aggressive and territorial. </p>
<p>Our two videos show the typical response of oversized and regular workers. </p>
<p>In the first video, each encounter between a yellow crazy ant and green tree ant ends with the green tree ant rapidly retreating, often after having her legs bitten and pulled by the yellow crazy ant. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RyOwB7o92Vs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>In the second video, you can see how oversized workers were more sedentary, less aggressive and less likely to start fighting with the green tree ant than normal workers in the first video. They were also less likely to kill their oppon-ant. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/38aE8H4GrJA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<p>It seems oversized workers are lazy and would be ineffective at defending the colony. So why do they occur at all?</p>
<h2>Like walking vending machines</h2>
<p>Generally, ant colonies need workers to function and only the queen can produce this caste. In the ant world, the death of the queen signifies the death of the colony. </p>
<p>However, if the queen dies after laying eggs, including one destined to become a queen, then the virgin queen who eventually emerges can mate with a worker-produced male. This is important because males are unlikely to be present unless the colony is very large.</p>
<p>So while workers lack organs for receiving and storing sperm, their ability to produce males asexually may extend the life of the colony. </p>
<p>What’s more, oversized workers can produce sterile eggs as well, which <a href="https://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-017-0210-4">serve as food</a> for the queen and other colony members. We believe these workers may be like walking vending machines within the colony, providing food when conditions aren’t suitable for foraging.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A male yellow crazy ant with one female eye and one male eye." src="https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=616&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=616&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=616&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=774&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=774&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395889/original/file-20210420-21-orexxu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=774&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A male yellow crazy ant with one female eye and one male eye.</span>
<span class="attribution"><span class="source">Pauline Lenancker</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We also found males with mismatched eyes. These odd-looking individuals may possess a female eye on one side and a smaller male eye on the other side. </p>
<p>Such individuals are potentially sex mosaics, with male and female genes spread across their body in patches. Whether these individuals function as normal males is a question for further research.</p>
<h2>What’s next?</h2>
<p>Researchers don’t know the full story of yellow crazy ant reproduction, but it’s likely to be highly complex and potentially unique. Our study contributes to solving this mystery. </p>
<p>Eradication and control programs for yellow crazy ants will benefit from understanding their reproductive system and behaviour. It can shed light on how even a few workers and eggs — who may be inadvertently moved around by humans or persist after control treatment — could eventually build into large numbers.</p>
<p>Likewise, understanding foraging behaviour is useful for planning insecticidal baiting, because effective baiting relies on foraging ants bringing bait back to the colony to share with queens and larvae. </p>
<p>We have no doubt future genetic work and experiments will shed further light on the fascinating reproductive biology of yellow crazy ants.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bridges-highways-scaffolds-how-the-amazing-engineering-of-army-ants-can-teach-us-to-build-better-158326">Bridges, highways, scaffolds: how the amazing engineering of army ants can teach us to build better</a>
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</p>
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<img src="https://counter.theconversation.com/content/158426/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Pauline Lenancker has received funding from the Skyrail Rainforest Foundation and the Ecological Society of Australia through the Holsworth Wildlife Research Endowment and Student Research Award.</span></em></p><p class="fine-print"><em><span>Lori Lach receives funding from the Australian Research Council, the Wet Tropics Management Authority, and the Department of Agriculture, Water, and the Environment. She has previously received funding from Kuranda Envirocare. She is a member of the National Exotic Invasive Ant Scientific Advisory Group. </span></em></p>Yellow crazy ants are one of the world’s worst invasive species. And it turns out they have unique systems of reproduction that make life in the queendom more complicated than we realised.Pauline Lenancker, Research scientist, James Cook UniversityLori Lach, Associate Professor, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1583262021-04-19T20:13:53Z2021-04-19T20:13:53ZBridges, highways, scaffolds: how the amazing engineering of army ants can teach us to build better<figure><img src="https://images.theconversation.com/files/395419/original/file-20210416-23-1axomur.JPG?ixlib=rb-1.1.0&rect=38%2C31%2C5098%2C3414&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Chris R Reid</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Army ants (<em>Eciton burchellii</em>) are known for their vast foraging raids. Hundreds of thousands of ants flow like a river from their nest site, scouring the jungle as they prey on anything unable to escape the swarm. </p>
<p>These raids are enormous undertakings. A single raid can be 20 metres wide and 100 metres long, comprising more than 200,000 ants, running at 13 centimetres per second, and gathering up to 3,000 prey objects per hour.</p>
<p>To ensure traffic flows efficiently, army ants construct highways and bridges along the rough forest floor. These structures are built entirely out of worker ants that join their bodies together. </p>
<p>How these tiny, <em>blind</em> ants manage to coordinate these dynamic constructions remains largely unknown, but a new study brings us closer to the answer.</p>
<p>New <a href="https://www.pnas.org/cgi/doi/10.1073/pnas.2013741118">research published</a> in the Proceedings of the National Academy of Sciences describes, for the first time, a type of self-assembled ant structure called a “scaffold”. </p>
<p>It also introduces a mathematical model for how scaffolds are formed, which could have implications for several fields of engineering.</p>
<h2>Scaffolds for army ant safety</h2>
<p>The research shows scaffolds act like a safety net for foraging army ants. They prevent walking ants from slipping and falling when their trail runs along steep ground. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/46sCtsl6ESE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Army ant scaffolds form up a wall (Chris R Reid)</span></figcaption>
</figure>
<p>The authors stalked the forests of Panama to find ant swarms, then redirected their trails along a platform that could tip between 20 and 90 degrees from a horizontal position. </p>
<p>The ants rarely formed scaffolds on slopes less than 40 degrees steep, while steeper inclines led to larger and faster-growing structures. Scaffolds were also more likely to be built when many workers were transporting heavy prey items. </p>
<p>And once a scaffold was in place, the number of falling ants would drop nearly to zero — even across a vertical surface.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/qxIiMFs2gRg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Army ant scaffolding forming on steep trail (Simon Garnier)</span></figcaption>
</figure>
<h2>Amazing self-assembling architects</h2>
<p>Ants are masters of collective architecture. Several species are documented to self-assemble into functional structures to overcome challenges in their habitats. </p>
<p>For instance, weaver ants (of the genus <em>Oecophylla</em>) line up in teams to form “pulling chains”, acting as living winches to bend leaves together when building their treetop nests. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/A2zqGoE8cYQ?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Weaver ants form pulling chains to roll a leaf to nest in (Chris R Reid)</span></figcaption>
</figure>
<p>Entire colonies of fire ants (<em>Solenopsis invicta</em>) escape flooding by forming floating rafts that can sail for several days, until the water retreats and the colony can safely land ashore. </p>
<p>Army ants (of the genus <em>Eciton</em>), however, have mastered this ability and extended it to almost every aspect of their biology. Along a single foraging raid, army ants can form hundreds of pothole plugs. </p>
<p>Their bridges, which span several ant body-lengths, help ease their passage over the irregular ground of Central and South America’s rainforests. At the end of each day the entire colony self-assembles into a huge hanging nest called a “bivouac”. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=496&fit=crop&dpr=1 600w, https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=496&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=496&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=624&fit=crop&dpr=1 754w, https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=624&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/393517/original/file-20210406-17-r5s68s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=624&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A bivouac disassembling during emigration.</span>
<span class="attribution"><span class="source">Chris R Reid</span></span>
</figcaption>
</figure>
<p>The study published today adds “scaffolds” to the existing list of structures built by army ants to sustain their fast-paced lifestyle.</p>
<p>Self-assembling into structures which are orders of magnitude larger than an individual requires an extreme degree of coordination. </p>
<p>Strikingly, this is achieved without any leaders or external blueprints. Each individual can only respond to local interactions with its neighbours and changes in the environment. </p>
<p>Discovering how these one-on-one interactions among individuals lead to complex group formations presents a challenge for biologists, and a golden opportunity for engineers. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/six-amazing-facts-you-need-to-know-about-ants-100478">Six amazing facts you need to know about ants</a>
</strong>
</em>
</p>
<hr>
<h2>Working on yourself for the good of the team</h2>
<p>Scientists have a name for when relatively simple animals display sophisticated behaviour at a group level: “emergence”. </p>
<p>Take the mesmerising undulations flowing through groups of starlings as they evade predators in the air, or the lightning-fast escape waves seen in schools of fish. Such coordination was <a href="https://www.amazon.com/Thought-transference-what-birds-Edmund-Selous/dp/B00085QJ1Q">once thought</a> to be the result of telepathic communication between group members.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/393511/original/file-20210406-15-1s8aj25.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A weaver ant pulling chain.</span>
<span class="attribution"><span class="source">Chris R Reid</span></span>
</figcaption>
</figure>
<p>Scientists now know simple one-on-one interactions can add up to more than the sum of their parts, explaining much about group-level patterns. But they’ve yet to fully understand how information at an individual level is combined and filtered to translate to a group-level response.</p>
<p>The recent research on army ant scaffolds provides new insight on this front, by developing a theoretical model of scaffold construction that centres around a simple mechanism. </p>
<p>That is: ants can sense how much they are slipping, and are more likely to stop and join scaffolds when their rate of slipping is high.</p>
<p>The ants don’t have to communicate with each other or assess the size of the structure. The properties of the group are modified simply by individuals sensing and correcting their own errors.</p>
<h2>Future applications</h2>
<p>The ability to form complex, adaptive structures using a minimum amount of sensing and information processing is extremely valuable to many engineering fields. </p>
<p>It could assist with the rapid production of biological products (biofabrication), designing self-healing materials such as metals or plastics that repair themselves when damaged, and in swarm robotics.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=603&fit=crop&dpr=1 600w, https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=603&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=603&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=758&fit=crop&dpr=1 754w, https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=758&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/395290/original/file-20210415-24-net8p5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=758&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Weaver ants form a hanging chain.</span>
<span class="attribution"><span class="source">Daniele Carlesso</span></span>
</figcaption>
</figure>
<p>For instance, a swarm of simple, cheap and largely expendable robots could be deployed to autonomously explore dangerous environments such as disaster zones. </p>
<p>The swarm could self-assemble into structures that may help it bridge large gaps, or shore up a crumbling building – all the while locating and rescuing survivors. </p>
<p>Crucially, these abilities wouldn’t need to be explicitly programmed into the robots’ behavioural repertoire. </p>
<p>Rather, the abilities would “emerge” from simple rules about how the robots should interact with each other, allowing the swarm to adapt to new environments like never before.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/these-ants-have-evolved-a-complex-system-of-battlefield-triage-and-rescue-94778">These ants have evolved a complex system of battlefield triage and rescue</a>
</strong>
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<img src="https://counter.theconversation.com/content/158326/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Reid receives funding from the Hermon Slade Foundation and the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Daniele Carlesso receives funding from the Australian Research Council. </span></em></p>A type of structure called a ‘scaffold’ acts like a safety net for ants when they go foraging, preventing them from slipping on steep surfaces.Chris R. Reid, DECRA Research Fellow, Macquarie UniversityDaniele Carlesso, PhD Candidate, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1576612021-03-28T13:39:18Z2021-03-28T13:39:18ZAnt invasion: How pets become pests<figure><img src="https://images.theconversation.com/files/391949/original/file-20210326-21-nhpyhk.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1022%2C680&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The European fire ant, Myrmica rubra, is one of the invasive ant species in Ontario. They are known for their painful sting. </span> <span class="attribution"><span class="source">(Jon Sanders)</span>, <span class="license">Author provided</span></span></figcaption></figure><p>When I was a teenager, I volunteered in the rainforest exhibit at an aquarium. A few times a week, we’d get a phone call from someone looking to donate a pet that they could no longer care for. Mostly turtles and frogs. The occasional parrot. Once, a retired dancer wanted to find a new home for two boa constrictors that had been part of her act. </p>
<p>But the aquarium could not take all the animals it was offered, and I often wondered what happened to all those unwanted pets. Many likely found new homes, but some were probably released into local parks or ponds, unfortunately.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Two men walk through a wooded area carrying a long python over their shoulders." src="https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391950/original/file-20210326-19-1noas4c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This four-metre, 43-kilogram female Burmese python was discovered a couple of metres from an upscale housing development in Naples, Fla. Most experts believe released pet pythons established a breeding population in the mid-1990s.</span>
</figcaption>
</figure>
<p>A recent study by researchers at the University of Lausanne <a href="https://doi.org/10.1073/pnas.2016337118">warns that the pet trade is contributing to the spread of invasive species around the globe</a>. The study, published in the <em>Proceedings of the National Academy of Sciences (PNAS)</em>, found that traded pets are often invasive species, meaning they establish natural populations in new places. </p>
<p>These pets are not just larger animals that are sometimes released in the wild when they outgrow their cages, like <a href="https://www.smithsonianmag.com/science-nature/snakes-ate-florida-180972534/">the Burmese pythons that have invaded the Florida Everglades</a>, but even a relatively new and apartment-friendly pet: ants. </p>
<h2>Ants are popular pets</h2>
<p>I study ants, which makes me a myrmecologist, and I sometimes keep live ant colonies for research purposes in my lab. At one point, I had nearly 100 live ant colonies for <a href="https://doi.org/10.1111/1365-2656.13310">a study comparing invasive and native ants as seed dispersers</a>.</p>
<p>I collect wild ant queens and workers from a <a href="http://ksr.utoronto.ca/">biological station</a> near me and house them in test tubes, which I wrap in tin foil and partially fill with wet cotton. This keeps the test tubes moist and dark, and usually the queen and her workers will move right in. </p>
<figure class="align-center ">
<img alt="A test tube holding ants and sealed with cotton balls." src="https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391953/original/file-20210326-25-hbxn4p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A queen ant and others in an ant farm starter test tube.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Because ants are easy to care for and downright fascinating to watch, they are growing rapidly in popularity as pets. According to the <em>PNAS</em> study, at least 65 websites now sell and ship ants all over the world. </p>
<p>As a myrmecologist, I am thrilled that others are finding joy in ants. Ants have complex social lives, play important roles in ecosystems and are capable of truly remarkable things. </p>
<p>Some ants join their bodies together into <a href="https://doi.org/10.1073/pnas.1016658108">floating rafts</a> or <a href="https://doi.org/10.1073/pnas.1512241112">bridges</a> to cross water or other obstacles. Others are clever enough to <a href="https://doi.org/10.1073/pnas.85.14.5287">figure out and remember the most direct route home</a>. </p>
<p>One of the ant species that I study <a href="https://doi.org/10.1038/437495a">creates enormous gardens of its host plants in the Amazon rain forest by poisoning all other plants with formic acid</a>. There are well over 15,000 species of ants on Earth, and they live on every continent except Antarctica. <a href="https://www.popularmechanics.com/space/a14883/ants-in-space/">Ants have even been to space</a>. </p>
<p>I love ants, so I can’t blame people for wanting ants as pets. </p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/4BdjxYUdJS8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Ants have complex social behaviours and can work together to solve problems, including building a bridge to transfer food across an open space.</span></figcaption>
</figure>
<h2>Pet ants are often invasive species</h2>
<p>But some ant species are also very serious pests. </p>
<p><a href="http://www.iucngisd.org/gisd/100_worst.php">Five ant species — Argentine ants, red imported fire ants, yellow crazy ants, little fire ants and big-headed ants — are among the top 100 worst invasive species in the world</a> because they can have devastating impacts on local ecosystems. Invasive ants often <a href="https://doi.org/10.1007/s004420000572">out-compete native insects</a>, <a href="https://doi.org/10.1007/s10530-017-1516-z">harm ground- and burrow-nesting birds</a> and <a href="https://doi.org/10.1098/rspb.2014.2846">help spread other pest species</a>.</p>
<p>The <em>PNAS</em> study found 520 ant species are traded as pets, and of those, 57 species (or 11 per cent) are known to be invasive, compared to just 1.7 per cent of ants overall. Interestingly, the pet trade in ants is new enough that those 57 invasive ant species were probably not introduced to new parts of the world by pet owners. </p>
<p>Instead, the new research emphasizes that the same traits that make animals good pets often make animals good invaders. For example, <a href="https://conbio.onlinelibrary.wiley.com/doi/abs/10.1046/j.1523-1739.2003.02018.x">invasive ant species commonly have colonies with more than one queen</a>, and ant species with multiple queens are also more commercially successful pets. </p>
<figure class="align-center ">
<img alt="Ants crawling over a pale gecko" src="https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=432&fit=crop&dpr=1 600w, https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=432&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=432&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=543&fit=crop&dpr=1 754w, https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=543&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/392034/original/file-20210326-19-18gt6hn.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=543&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Yellow crazy ants attacking a gecko in India.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:YellowCrazyAnt-Dinakarr-4May11.JPG">(Dinakarr/Wikimedia)</a></span>
</figcaption>
</figure>
<p>Because some of the ants I study in my lab are invasive species, my lab members and I take extra care to make sure our ants do not escape. We put the ants’ test tube nests in plastic Tupperware containers that we coat with a special substance called Fluon, a milky white resin that makes the walls of the containers so smooth that ants can’t climb up them. Then we put the containers on shelves that have legs that sit in little bowls of mineral oil. If a wayward ant happens to make a run for it, she’ll get stuck in the oil before she can get to the door. </p>
<p>But people keeping ants or other invasive animals as pets may not be as cautious. </p>
<p>Fortunately, there is an easy fix: do a little homework when looking for a new pet, and consider choosing a species that is native to your area. </p>
<p>Ant enthusiasts can even collect a colony locally. Ants are so diverse and abundant that there is good chance that you can find an interesting and suitable native ant species near you, wherever you are in the world. Just remember <a href="https://askabiologist.asu.edu/explore/collecting-ants">you have to find a queen to keep the colony going</a>. Then, sit back and indulge your love of ants.</p><img src="https://counter.theconversation.com/content/157661/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Megan Frederickson receives funding from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Gordon and Betty Moore Foundation.</span></em></p>Animals that are traded as pets are more likely to be invasive species, including a relatively new pet: ants.Megan Frederickson, Associate Professor of Ecology & Evolutionary Biology, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1526522021-01-21T13:13:27Z2021-01-21T13:13:27ZInvasive tawny crazy ants have an intense craving for calcium – with implications for their spread in the US<figure><img src="https://images.theconversation.com/files/378340/original/file-20210112-23-1duz31c.png?ixlib=rb-1.1.0&rect=6%2C6%2C4019%2C3011&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Multiple queens ensure colonies have a steady output of workers.</span> <span class="attribution"><span class="source">Ryan Reihart</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p><em>The <a href="https://theconversation.com/us/topics/research-brief-83231">Research Brief</a> is a short take about interesting academic work.</em></p>
<h2>The big idea</h2>
<p>In a recent study, <a href="https://chelseprather.wordpress.com/">my colleagues</a> and <a href="https://scholar.google.com/citations?hl=en&user=6GBgzO8AAAAJ">I</a> discovered micronutrients in the ground <a href="https://www.doi.org/10.1002/ECY.3263">can control populations of invasive crazy ants</a> (<em>Nylanderia fulva</em>). </p>
<p>Tawny crazy ants – named for their fast, erratic movements – can blanket the ground by the millions. Originating in South America and now established in parts of the southern U.S., they <a href="https://www.nytimes.com/2013/12/08/magazine/crazy-ants.html">harm other insects, asphyxiate chickens and even short-circuit electronics in homes</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close up photo of a golden-colored ant against a blue background." src="https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378389/original/file-20210112-23-1urj0n3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">At only 0.125 inches (3.2 mm) long, crazy ants are tiny but mighty.</span>
<span class="attribution"><span class="source">Ryan Reihart</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Crazy ants are <a href="https://doi.org/10.1146/annurev.ecolsys.33.010802.150444">liquid feeders</a> <a href="https://doi.org/10.1653/024.096.0219">that consume nectar from plants – and honeydew (or secretions) from certain insects</a>. Ants crave these sugary resources, which <a href="https://doi.org/10.1073/pnas.1115263108">boost their colony growth</a>, enabling them to outcompete native species and ultimately spread. </p>
<p>The nutritional content of nectar and honeydew vary widely, however, <a href="https://www.britishecologicalsociety.org/ant-cravings-sugar-salt-vary-across-us/">depending on the nutrients available in a particular ecosystem</a>. There are 25 chemical elements required to build life – too much or too little of one may cause disease. So far, ecologists only really know about the importance of macronutrients, like nitrogen and phosphorus, that are abundant in living tissue. My team wanted to learn more about what micronutrients might be important to crazy ants.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man kneeling over a small hole dug in the grass." src="https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=801&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=801&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=801&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1007&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1007&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377606/original/file-20210107-20-1t2ehyf.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1007&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Installing a pitfall trap in one of the 128 fertilized study plots.</span>
<span class="attribution"><span class="source">Kiersten Angelos</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We conducted a fertilization experiment at the <a href="http://www.eih.uh.edu/">University of Houston’s Coastal Center</a> and were able to demonstrate that the abundance of tawny crazy ants decreased 24% where there was more potassium and 45% where there was more sodium and potassium. </p>
<p>What greatly surprised our team was the discovery that ants were 13% more abundant in areas where there was more calcium – even in areas that had more sodium and potassium. This finding, <a href="https://www.doi.org/10.1002/ECY.3263">published in the journal Ecology</a>, could have big implications for the continued spread of crazy ants. </p>
<h2>Why it matters</h2>
<p>Ours is the first study showing calcium is important to an invasive ant, which is somewhat surprising given ants don’t have bones. It turns out, though, calcium is important in their <a href="https://doi.org/10.1016/j.ceca.2012.11.008">egg production</a>, <a href="https://doi.org/10.1080/00218839.2015.1035074">larval development</a> and <a href="https://doi.org/10.1093/aesa/51.2.142">physiological regulation</a>. </p>
<p><a href="https://doi.org/10.1002/ece3.1737">If the spread of crazy ants continues north</a>, the calcium-rich limestone bedrock of the lower U.S. Midwest may provide ideal conditions for populations to explode. Farmlands may be at risk because calcium is found in many fertilizers. Additionally, cities often have <a href="https://doi.org/10.1007/s10980-008-9288-6">more calcium than surrounding areas</a>, thanks to heavy cement use, limestone quarrying and destruction of buildings.</p>
<p>Tawny crazy ants not only are a major threat to the biodiversity and conservation of ecosystems but also <a href="https://doi.org/10.1038/ncomms12986">cost the U.S. billions of dollars in damage annually</a>. </p>
<h2>What still isn’t known</h2>
<p>Our results add to a small but <a href="https://doi.org/10.1111/geb.13196">growing list</a> <a href="https://doi.org/10.1111/ele.13517">of other experiments</a> <a href="https://doi.org/10.1111/ele.13127">that show the importance of micronutrients</a> to insects. </p>
<p>How far will tawny crazy ants make it in the United States? Will calcium influence their spread? Could other micronutrients like magnesium or iron be important to crazy ants?</p>
<p>In a world where <a href="https://doi.org/10.1126/science.1259855">humans are changing the “ingredients” of Earth’s surface soils</a> at an alarming rate, people may be unwittingly creating more favorable habitats for some invasive species. Figuring out which elements are most important to invasive species will be key to predicting, preventing and managing their spread.</p><img src="https://counter.theconversation.com/content/152652/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ryan Reihart receives funding from the National Science Foundation (NSF) Division of Environmental Biology (DEB) grants 1457114 and 1724663 and from the University of Dayton Office for Graduate Academic Affairs through the Graduate Student Summer Fellowship Program. </span></em></p>The spread of tawny crazy ants may be driven, in part, by their need for calcium. The calcium-rich limestone bedrock of the lower U.S. Midwest may provide ideal conditions for populations to explode.Ryan Reihart, Teaching Assistant and Ph.D. Candidate of Ecology, University of DaytonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1527202021-01-20T13:31:45Z2021-01-20T13:31:45ZStickiness is a weapon some plants use to fend off hungry insects<figure><img src="https://images.theconversation.com/files/377854/original/file-20210108-15-ukf9cf.JPG?ixlib=rb-1.1.0&rect=23%2C17%2C3858%2C2549&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A coat of sand makes an effective armor.</span> <span class="attribution"><span class="source">Eric LoPresti</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Imagine the texture of a plant. Many may come to mind – the smooth rubberiness of many tropical houseplants, the impossibly soft lamb’s ear, the sharp spines of cacti, or the roughness of tree bark. But stickiness, in the flypaper-stick-to-your-fingers sense, probably isn’t at the top of your list. </p>
<p>Nevertheless, a great many <a href="https://www.doi.org/10.1890/15-0342.1">plants have evolved sticky leaves</a>, stems and seeds, including some you likely know – such as petunias and tobacco. </p>
<p>In evolutionary biology, a trait that has evolved many times is interesting, since it suggests that over and over this trait serves some benefit. While people have noticed and discussed this odd characteristic for a great many years, <a href="https://scholar.google.com/citations?hl=en&user=7l5UAp4AAAAJ">biologists like me</a> are finally beginning to understand what stickiness is for – and why so many plants have it. </p>
<h2>Sand and stickiness</h2>
<p>Sticky plants are widespread. They are found in temperate and tropical areas, in wet and dry places and in forests, fields and dunes. In each of these environments, stickiness functions somewhat differently. </p>
<p>I am naturally drawn to sand dunes, whether in dry deserts or along beautiful coastlines, and stickiness has some interesting functions for plants in these locations. Shifting sand presents a challenging environment for plants – sand-blasting winds, potential burial and the lack of water retention are just a few.</p>
<p>Interestingly, hundreds of <a href="https://www.doi.org/10.1002/fedr.19961070510">plant species in sand dunes have evolved sticky surfaces</a>, suggesting utility in that habitat. Windblown sand coats these sticky surfaces – a phenomenon known as psammophory, which means “sand-carrying” in Greek. While a sandy coating may limit light from reaching plant surfaces, it also likely protects plants from abrasion and reflects light, reducing leaf temperature. It also defends plants from hungry predators.</p>
<p>A few years ago, my colleagues and I <a href="https://www.doi.org/10.1890/15-1696.1">studied yellow sand verbena (<em>Abronia latifolia</em>) plants in coastal California</a>. When we gently removed sand from leaves and stems, those leaves and stems got eaten by hungry snails, caterpillars and other herbivorous animals at twice the rate of sand-intact leaves and stems.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A close up of plant leaves covered in green tinted sand." src="https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378083/original/file-20210111-23-my6dah.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Leaves covered in colored sand to test whether camouflage is a factor.</span>
<span class="attribution"><span class="source">Eric LoPresti</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>We wondered if the sand might be protecting plants by camouflaging them. With a second experiment, we carefully cleaned and re-coated some verbena leaves with tinted sand that didn’t match the background. It turned out the color of the sand didn’t matter – <a href="https://www.doi.org/10.1890/15-1696.1">predators ate the sand-covered leaves at the same rate</a>, regardless of whether they blended with their background or not – showing sand protects plants as a physical barrier, rather than as a camouflage.</p>
<h2>Wearing down mouthparts</h2>
<p>This result makes intuitive sense – after all, who wants to eat something covered in sand, even if it is nutritious? Yet I’ve observed over the years that a great many herbivorous insects do indeed eat sandy leaves. It got me wondering what effect the sand might be having on them, so we did a series of simple experiments. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A microscopic view of two different sets of mandibles. One shows pointy 'teeth,' while the other looks worn down." src="https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=242&fit=crop&dpr=1 600w, https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=242&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=242&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=305&fit=crop&dpr=1 754w, https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=305&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/377857/original/file-20210108-23-1w4o9js.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=305&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The mandible of a caterpillar eating clean leaves (left), versus the worn-down mandible of one eating sand-encrusted leaves (right).</span>
<span class="attribution"><span class="source">Eric LoPresti</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>When we gave caterpillars a choice between eating sand-free and sand-covered plants, <a href="https://www.doi.org/10.1111/een.12483">they overwhelmingly chose to eat sand-free plants</a>. When we gave caterpillars no choice – one group getting only sandy leaves, the other getting clean leaves – we observed the mandibles, or mouthparts, of the sand eaters were noticeably worn down. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Close up shot of a caterpillar's stomach contents, which show grains of sand amid digested leaves." src="https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378319/original/file-20210112-21-15ryy0c.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The gut contents of a caterpillar fed sand-coated leaves. Note the many grains of sand present.</span>
<span class="attribution"><span class="source">Eric LoPresti</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>The sand-eating caterpillars also <a href="https://www.doi.org/10.1111/een.12483">grew about 10% more slowly</a> than those fed on nonsandy foliage, we suspect in part because they were ingesting some sand.</p>
<h2>Sticky seeds</h2>
<p>In sandy areas, it’s also common to find seeds that become sticky when moistened. Such seeds are coated in mucilage, which are simple carbohydrates that, in the presence of water, become a sticky mess. Even when they dry out, they can become sticky again, virtually indefinitely. You may be familiar with this phenomenon in chia seeds – mucilage is what gives chia pudding its distinctive texture. </p>
<p>When a mucilage-coated seed falls into sand, gets moistened by rainfall or dew and then dries, it becomes encrusted in a heavy coating of sand. This extra weight <a href="https://www.doi.org/10.1002/ecy.2809">makes it difficult for carpenter ants to carry the seeds back to their nests to consume</a>. </p>
<figure>
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<figcaption><span class="caption">The struggle is real. <i>Eric LoPresti</i></span></figcaption>
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<p>We demonstrated this by making feeding stations where we could measure removal rates of sand-covered seeds and bare seeds. In nearly all of the 53 plant species we tested, the <a href="https://www.doi.org/10.1002/ecy.2809">sandy seeds were removed far more slowly than the bare seeds</a>.</p>
<p>While plant stickiness in sandy areas creates a barrier to stop herbivores, in other habitats it operates differently. For example, some carnivorous plants use stickiness to catch prey. </p>
<p>Every bit of a plant is shaped, over millions of years, by having to confront the challenges of the world around it while remaining rooted in a single place. Stickiness is one of thousands of strategies plants have stumbled on to survive the onslaught of hungry animals in nature. </p>
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<p class="fine-print"><em><span>Eric LoPresti received funding from the National Science Foundation. </span></em></p>For some sand-dwelling plants, stickiness is a defense tactic that keeps predators at bay.Eric LoPresti, Assistant Professor of Plant Biology, Ecology and Evolution, Oklahoma State UniversityLicensed as Creative Commons – attribution, no derivatives.