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Scientists have moved a step closer to understanding why mosquitoes bite some people far more often than others. The answer appears to lie in a complex chemical “cocktail” produced by the human body, according to a report by Science Alert.
“It’s not a coincidence that mosquitoes are more attracted to some people than others. But not all of us are mosquito magnets all the time,” said Frédéric Simard of the French Research Institute for Sustainable Development.
Female mosquitoes, which are responsible for biting humans, rely on a combination of sensory signals to find their targets. These include the carbon dioxide people exhale, body heat, humidity, and, most importantly, body odor.
Scientists have known for more than a century that carbon dioxide acts as the first signal, helping mosquitoes detect humans from dozens of meters away. As they get closer, they begin to analyze skin odors, while body temperature and moisture help them identify the most attractive target.
Researchers say several popular beliefs are incorrect. There is no proven connection between mosquito attraction and blood type, hair color, eye color, or skin color. Instead, the key factor is the unique mix of compounds produced by bacteria living on human skin.
“The combination of molecules produced by our microbiota can be more or less attractive to mosquitoes,” Simard explained.
Humans release between 300 and 1,000 different odor compounds, and scientists are still trying to determine which ones matter most.
In a recent study, researchers led by Swedish scientist Rickard Ignell exposed 42 women to Aedes aegypti mosquitoes, a species known for spreading dengue fever and yellow fever. The team identified 27 odor compounds that appeared to influence mosquito behavior.
Women who received the most bites—including pregnant women in their second trimester—produced higher levels of a compound called 1-octen-3-ol, also known as “mushroom alcohol.” Even small increases in this substance significantly increased mosquito attraction.
Previous research has also shown that alcohol consumption, particularly beer, can make people more attractive to mosquitoes. Beer increases carbon dioxide production and alters body odor. A 2023 study in the Netherlands found that people who had consumed beer within the previous 24 hours were 1.35 times more attractive to mosquitoes than those who had not.
Scientists believe these findings could eventually help develop more effective mosquito repellents and strategies to prevent mosquito-borne diseases.
Researchers have also warned that some mosquito species are becoming increasingly dependent on human blood, a shift that may be driven by human activity and environmental changes.
