It’s quite a romantic notion that the sweetness of our blood attracts mosquitoes. But in reality, it’s probably the cocktail of stinky microbes on our skin that really draws them in.
It’s hard to know where this myth started. Perhaps because some insects are known pollinators and attracted to nectar and other plant juices, it was considered that mosquitoes behave similarly? Mosquitoes do feed on plant sugars and this has been exploited in the development of new mosquito-borne disease surveillance strategies in Australia and North America.
As the saying goes, a spoonful of sugar helps the medicine go down. Perhaps consoling a mosquito bite-covered friend with the words “it must be your sweet blood” can take the edge off the itch?
It is true that only female mosquitoes bite. She bites to get a hit of protein required for egg development, but preferences for that blood can vary greatly. Some prefer to bite mammals. Some prefer birds. Some even prefer to bite frogs. And, unfortunately, some prefer to bite humans.
There is strong evidence that we all differ in our attractiveness to biting mosquitoes. They are firstly attracted by the carbon dioxide we exhale. Body heat plays a role in attraction too. But while mosquitoes may bite us to get a feed of blood, our blood itself doesn’t seem to influence who they bite.

Although studies have suggested that mosquitoes are more attracted to individuals with Type O blood, the results are far from conclusive. The trend isn’t likely to be consistent for all mosquito species either and it certainly isn’t only those people with Type O blood that get bitten.
Odours produced by microbes on our skin have been shown to attract mosquitoes – and there can be quite a cocktail of smells emanating from us. More than 300 chemical compounds have been identified from human skin and the abundance of some of these can vary on a daily basis. Differences in the attractiveness of individuals to mosquitoes may be explained by differences in the abundance and diversity of these microbes.
Keep in mind that not all these compounds will attract mosquitoes. Some will actually reduce the likelihood of being bitten.
So what does this all mean for those wanting to be less attractive to mosquitoes?
Researchers may one day produce new repellents or more effective mosquito traps but the take-home message from decades of research is that everyone varies a little in their attractiveness to biting mosquitoes. You may never know exactly why you get bitten more than your friends.
Remember, it only takes one bite for the transmission of a disease-causing pathogen, so even if you don’t think you’re top of the list on a mosquito’s menu, take precautions to prevent bites.
Sue Ieraci
Public hospital clinician
Isn't the other factor operating here the individual's immune response to the bite? I am one of these people who gets big lumps that can last weeks, while others alongside me can be bitten but recover quickly.
Peter Fox
Peter Fox is a Friend of The Conversation.
Medical doctor
My favourite mosquito related myth is that liberal consumption of Gin & Tonics prevents malaria. Tasty, although it may be when in the tropics, it is unlikely to make any difference to malaria transmission.
True, tonic water often contains small amounts of quinine, but the legal maximum is about 80 mg per litre (however most brands contain anywhere from 0 to 50mg/L). The typical loading dose for treatment of malaria is around 1400mg, equivalent to about 30 litres of tonic water. And the maintenance dose (about 15 litres) has to be repeated every 12 hours. Secondly, quinine isn't much good for prevention of malaria anyway.
Bob Buick
Retired medical consultant
Don't laugh - I'm well familiar with the pitfalls of anecdotal evidence. However, I was plagued by mosquito and midge bites for years and reluctant to venture outdoors without lashings of DEET, until I read an article a couple of years ago about the repellent quality of Thiamine. I began taking 100mg daily with my morning coffee, curious to find whether it might work. The result has been striking. I have had only three bites in the last two years, here on the bushy fringe of the Gold Coast, despite completely abandoning all other repellents. My garden has become a great place to read and listen to music at last. It's unlikely to be an auto-immune change, as those very few bites have produced the same old reaction.
Does anyone else have supporting evidence for the repellent value of Thiamine, or its breakdown products, or am I just lucky?
Rick Fleckner
Student
I am convinced that my skin exuding a strong garlic aroma keeps the mozzies at bay, to a greater or lesser extent depending on how much garlic is consumed. Eating plenty of parsley helps to make it less offensive for other humans in my vicinity.
Brian Myerson
Director of not for profit organisation
I am a transplant recipient. A few years ago I was sitting in the transplant clinic when 2 recipients commented that they had not had a mosquito bite in ages. There was this amazing response of "me too" from all the others at the clinic. We asked our doctors who advised that they were not aware of any evidence to suggest that our immune suppression medication had any effect. I had my transplant 13 years ago and do not remember getting a single bite since then.
Nobody would choose to live on this medication but there must be a clever chemist who could identify what the cause is and come up with an effective compound.
Sue Ieraci
Public hospital clinician
Brian - it's likely that you are still getting bitten but your immunosuppressant medication stops you mounting an inflammatory reaction (itchy lump).
Brian Myerson
Director of not for profit organisation
Sue, thanks for that very interesting comment. I will be more observant while I am outside this summer. My brother is particularly "attractive" to mosquitoes and he has often commented, with envy, that the mosquitoes fly passed me and land on him. So who knows?
Peter Hindrup
consultant
Before I left the farm, on the infrequent occasions that both my father and I were milking the 'house cows', I would be being eaten alive by mosquitoes and what we called 'sand flies'. Blood would be streaming down my arms from the 'sand fly ' bites, dad would have nothing.
His theory was 'ignore them and they go away'. Easy when you are not being attacked!
(In New Zealand)