Why are some people mosquito magnets?

Scientists are now making progress in deciphering the complex chemical cocktail that makes particular people more enticing to these disease-spreading bloodsuckers.

A range of sensory cues can cause mosquitoes to pick one human over another — mainly the smell and heat our bodies give off, and the carbon dioxide we exhale. Female mosquitoes — which are the only ones that bite — detect these signals with finely-tuned receptors, then choose their target accordingly.

The idea that mosquitoes prefer particular blood types “has no scientific basis,” Frederic Simard of France’s Institute of Research for Development said. Odour, however, matters greatly: “A soup of molecules produced by our microbiota is more … appealing to mosquitoes”.

Humans release between 300 and 1,000 different odorous compounds, research has shown, but scientists are only just beginning to understand which ones attract mosquitoes.

In a recent study, researchers released Aedes aegypti mosquitoes on 42 women in a lab. The mosquitoes detected 27 odorous compounds. The women the mosquitoes most liked to bite produced a compound made by the breakdown of a skin oil called sebum.

Drinking beer has also been linked to attracting mosquitoes because it raises body temperature, increases the amount of exhaled CO2 and changes skin odour, according to several studies.

For a 2023 study in the Netherlands, 465 volunteers put their arms in cages filled with female Anopheles mosquitoes, which can spread malaria. The volunteers who had drunk beer in the previous 24 hours were 1.35-times more attractive to the mosquitoes.