Yes, Mosquitoes Do Love Some People More.
Have you ever gone on a group hike where you all forgot to pack your bug repellant, or perhaps had a backyard barbecue where the mosquitoes came out in full force? Chances are, by the end of the day, some people are covered in bites, while others are left with just one or two itchy spots. “Mosquitoes love me,” the unfortunate among you may remark. And this is probably true.
We’ve known for a long time that mosquitoes prefer some people over others, but finding out the reasons for this has been difficult. Spoiler alert: While scientists haven’t solved this mystery yet, we have a ton of clues.
Body size and activity
First, we know that mosquitoes are heading towards us by smelling the carbon dioxide we breathe out all the time. The bigger you are, the more oxygen you breathe in and the more carbon dioxide you breathe out. This means that mosquitoes find adults more easily than children, larger adults are easier to find than smaller ones, and you will be easier targets for mosquitoes when you are pregnant than when you are not.
We also breathe more when we exercise because we need more oxygen to burn off the calories that fuel that exercise. This results in more carbon dioxide. Therefore, when you are exercising, you are more of a target than when you are sitting still. Mosquitoes also detect our body heat, which also increases with exercise.
Dark clothes
As soon as mosquitoes discover our common territory, they fly towards large dark objects. People dressed in dark clothes get more mosquito bites than those wearing light-colored clothes . So when there are no mosquitoes, consider dressing in light colors. Some research shows that red or orange clothing is especially attractive to Aedes mosquitoes (the striped ones you find in the southern parts of the US), so you might want to stick with blue and green when choosing your pastel wardrobe.
Just like you smell
There are definitely other factors influencing who mosquitoes like, but scientists are still working on figuring out what they are. For example, drinking alcohol affects how attractive we are to insects .
But there is more. In one recent study, researchers asked people to wear stockings on their arms for several days to absorb their smell, and then exposed the stockings to mosquitoes. The Skeeters preferred one stocking over another, which is not surprising; The scientists’ plan was to genetically alter the sense of smell of mosquitoes and see if that prevents them from smelling some people or all people. This aspect of the experiment failed.
But in the process, it turned out that the differences between people were not subtle. One sample from Subject 33 was 100 times more attractive to mosquitoes than the least attractive sample. As the researchers reported to Sci Tech Daily:
The samples in the trials were de-identified, so the experimenters didn’t know which of the participants wore which nylon. However, they noticed that in any test involving Subject 33, something unusual happened, because insects swarmed to this sample. “This would have been obvious within seconds of starting the analysis,” says [researcher Maria Elena] De Obaldia.
Chemical analysis has shown that more attractive stockings contain high amounts of carboxylic acids, a family of chemicals that we produce in our sebaceous glands. Bacteria and other microbes that grow on our skin likely also affect this chemical profile (and possibly vice versa). So, we’re still learning why some people smell better like mosquitoes, but at least it’s clear that the difference is real.