You know the scene. One person at the barbecue is already slapping at their arms, while everyone else sips their drink in peace. The next morning they count the welts and wonder what makes them so special.
A new wave of research has narrowed the answer to a short list of chemicals your skin gives off. A 2026 study in iScience led by Rickard Ignell at the Swedish University of Agricultural Sciences tested 42 women against yellow fever mosquitoes.
Out of the up to 1,000 odors a human can emit, the team pinpointed 27 that drive the attraction. One stood out. The compound, 1-octen-3-ol, is a smell often called mushroom alcohol, formed when skin oil breaks down.
People who gave off more of it were far more attractive to Aedes aegypti, the mosquito behind dengue, Zika and yellow fever. Pregnant women in their second trimester were among those producing the most.
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What a beer and a pregnancy change about your scent
Beer is one of the clearest triggers. In a Dutch festival study posted on bioRxiv, researchers had 465 volunteers put a bare forearm into a cage of Anopheles mosquitoes, the group that carries malaria.
Those who had drunk beer in the past 24 hours were about 1.35 times as attractive to the insects as those who had not. The team linked it to shifts in body temperature, exhaled carbon dioxide and skin odor.
Pregnancy appears to work through the same chemistry. The second-trimester women in the Ignell test gave off more 1-octen-3-ol and were bitten more, which fits earlier field work showing pregnant women are bitten more in malaria regions.
Three mosquito species pick three different favorite people
A second 2026 iScience study points to another layer. Researchers at Florida International University exposed 119 volunteers to three disease-carrying mosquito species. Not a single person turned out to be the top target for all three.
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The team, led by mosquito neurobiologist Kaylee Marrero, tested Aedes aegypti, the Asian tiger mosquito and the southern house mosquito. Each species keyed in on a different mix of skin smells.
The microbes that live on your skin seem to do much of the work. Aedes aegypti and the southern house mosquito preferred people with less skin odor overall, and a strain of Staphylococcus was common among the people all three species liked best.
Where blood type fits in
If someone has told you your blood type is why mosquitoes love you, that part looks shakier.
Frederic Simard of France's Institute of Research for Development told France 24 the idea has "no scientific basis," noting that the few papers behind it involved very few participants.
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The research teams now plan to test whether certain skin microbes can be turned into repellents or lures for traps. For now, standard advice still holds. Cover exposed skin at dusk, use an EPA-registered repellent and sleep under a net in regions where mosquitoes carry disease.
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This article is made and published by Aksel Kryhlmand, who may have used AI in the preparation.