Mosquito bite risk tied to CO₂, heat and skin microbiome, study shows

Scientific research explains why mosquitoes bite some people more often than others. Mosquitoes locate hosts up to about 10 metres away using visual cues and, chiefly, olfactory signals such as carbon‑dioxide (CO₂) expelled in breath. Adults produce more CO₂ than children, and pregnant women emit higher levels of CO₂ and body heat, making them especially attractive.

Heat, moisture and the unique scent of each person’s skin also guide mosquitoes. Bacteria on the skin break down sweat and other compounds into volatile organic chemicals; the composition of these chemicals varies between individuals. Studies found that people with higher levels of certain carboxylic acids on their skin attracted up to 100 times more mosquito bites than those with lower levels. The skin microbiome, body temperature, metabolic rate and even factors like recent alcohol consumption can increase attractiveness.

Researchers from Wageningen University (Netherlands) and Rockefeller University (USA) demonstrated these mechanisms in laboratory experiments, confirming that the combination of CO₂, heat and skin‑derived odor determines which humans become mosquito targets. The findings have implications for personal protection and for developing new repellents that mimic unattractive scent profiles.