Mosquitoes Prefer Certain Humans Based on Body Chemistry, Study Finds

Scientists explain that mosquitoes select human hosts using a combination of sensory cues. Carbon dioxide emitted in breath is detected from several meters away, drawing the insects toward a person. As they close in, body odor—produced by skin microbiota—and body heat and moisture further increase attraction. French medical entomologist Frédéric Simard and Swedish researcher Rickard Ignell report that specific skin chemicals, notably the compound 1‑octen‑3‑ol, make some individuals more appealing. Laboratory work with Aedes aegypti showed the insects can discriminate among roughly 27 of the thousands of volatile compounds humans emit. The studies also found that pregnant women in their second trimester, who release higher levels of certain sebum‑derived chemicals, attract more bites. Additionally, alcohol consumption raises body temperature, CO₂ output, and alters skin odor, making drinkers up to 1.35 times more attractive to malaria‑transmitting Anopheles mosquitoes. Researchers note that climate change is expanding mosquito habitats, increasing the relevance of these findings for disease‑preventive strategies.