Ever wondered why you seem to get more mosquito bites than some of your friends? While you might think that mosquitoes choose their targets indiscriminately, there is actually a pretty scientific way by which mosquitoes decide who to bite.

But why do mosquitoes even bite humans? Feeding on human blood is a vital necessity for the life cycle of many mosquito species, including the three most common species in the U.S., the Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus mosquitoes. Human blood is an essential reproductive component for female mosquitoes, as without it they wouldn’t have the protein and iron needed to make their eggs. An unintended side effect of this, however, is the spread of dangerous disease to humans, such as Zika and West Nile virus.

When targeting humans, mosquitoes use a multi-faceted approach to choose their “victims,” sensing the carbon dioxide, body odor, humidity, and body heat emanating from your body. Anthrophilic, or mosquitoes that prefer humans as hosts, prefer environments with lots of people and are strongly attracted to body odor. Body odor, in this case, isn’t what you think it is. Our skin is constantly covered in odorless skin secretions. While these are odorless on their own, cutaneous (skin) bacteria are responsible for breaking down these secretions for their benefit. As a result they release thousands of different volatile organic compounds (VOCs) that can then be detected by mosquitoes. These bacteria break down the sweat, sebum (oil), and outermost layer of dead skin cells on our skin’s surface.

As mosquitoes use these highly unique VOCs as their scent cues, it is likely that mosquitoes target males and females differently, since the VOCs from the skin of both males and females are different. This logic holds true for some mosquito species, with a research article stating they found that Ae. aegypti were more attracted to males than females. Body odor and the bacteria found on participants’ skin was most influential in determining whether mosquitoes were highly attracted to these subjects. This “aura” of scent and VOCs is referred to as a volatilome. A person’s particular volatilome is most strongly associated with species-specific mosquito responses.

So, as it turns out, a mosquito’s attraction to a person is highly dependent on their specific volatilome — or simply put — the way they “smell” to a mosquito. The complex array of VOCs is what draws specific mosquitoes to a person. In some cases, being a male can make you more prone to attracting mosquitoes. This is just because of the unique VOCs that attract Ae. aegypti mosquitoes to humans. So if you find yourself getting more mosquito bites than everyone else, it’s not in your head — you may just happen to have a volatilome that the mosquito(es) around you find attractive.