Leeches suck blood because it is a very good food for them. Some leeches only need to feed once a year.
The short answer is that leeches need blood to grow and reproduce. But it's in their interests to do it carefully, without causing too much pain, and in spots that are hard to find.
Down House: the home (and garden) of Charles Darwin.
Was Darwin inspired by the tropical wildlife of his travels to discover natural selection? Actually, pigeons, worms and barnacles were far more prominent in his thinking.
The “hammerhead” of
Diversibipalium multilineatum. This species can reach 40 centimeters (16 inches) in length.
Several giant terrestrial Plathelminth species have invaded France and its overseas territories, threatening biodiversity. Thanks to participatory science, the invasion is finally recognized.
Cross-sections of the spermatozoa of the Monogene
Chimaericola leptogaster as seen under an electron microscope.
In biology, the study of these very special sperm cells makes it possible to learn more about species such as parasitic worms.
Parasites are not only a personal health problem – they are political too.
Worms do have something in their mouth that they can poke out, like a tongue. It is called a stylet.
The short answer is no. But worms can use different parts of their body to do some of the jobs that our tongues do - like tasting and crushing food.
Larvae of longhorn beetle feeding on pine stump.
It's thanks to decomposition brought about by beetles and fungi that we're not all buried under dead organic matter.
photographyfirm / shutterstock
We focus on large, charismatic animals at the expense of these crucial 'lowly creatures'.
Africa is home to a rich diversity of edible insects like mopani worms.
Insects have often been described with words like "disgusting" and the idea of eating them horrifies some people. But this needs to change as they can be an important food source.
Nematodes play an important role in all biological systems.
There is much more than just parasitic features when it comes to nematodes: these tiny creatures are vital to ecosystems.
A microscopic set of teeth helped scientists realise they had been looking at fossils of Hallucigenia back to front.
Threadworm infection is common but it’s often asymptomatic.
Intestinal worms (or helminths) are multicellular parasites that live inside the gut. When mature, they can generally be seen with the naked eye. In developing countries with poor sanitation, the most…
Head or tail?
A bizarre 500-million-year-old “worm with legs” has finally found its rightful place on the evolutionary tree of life. Fossils of Hallucigenia look so odd that scientists couldn’t make head or tail of…
A molecule in parasitic worms could explain why some worm infections can treat a range of autoimmune diseases, including…
Parasites can infest any part of the body that has an opening to the outside world.
Many microscopic bugs and bacteria live on our skin and within our various nooks and crannies. Almost anywhere on (or even within) the human body can be home to these enterprising bugs. Bugs affect us…
These little worms are very powerful model organisms, revealing important lessons about human biology.
Our series, Animals in Research, profiles the top organisms used for science experimentation. Here, we look at Caenorhabditis elegans – a roundworm. When you think of a worm, what do you see? For some…
A universal language employed by nematodes (or roundworms) has been discovered; a form of communication never seen before…