Why Are Some People More Prone to Mosquito Bites?

Our bodies emit biological signals through breath and skin that influence mosquito attraction.

Some people’s signals are especially appealing to mosquitoes.

Mosquitoes identify humans through three key methods.

Only female mosquitoes bite humans because they need protein to lay eggs, making human blood attractive to them.

They use their vision and sense of smell.

Mosquitoes can spot or smell their target from up to 10 meters away.

Carbon dioxide expelled from our breath and skin acts as a major signal to mosquitoes.

The carbon dioxide we exhale triggers mosquitoes’ food-seeking behavior.

Adults produce more carbon dioxide than children, which makes adult humans more attractive to mosquitoes.

Sometimes mosquitoes are also drawn to other sources of carbon dioxide beyond humans.

This is why dry ice and bottled carbon dioxide are used to trap mosquitoes.

Research shows mosquitoes also favor warmth and humidity. Carbon dioxide enhances this attraction.

Pregnant women are generally more attractive to mosquitoes than other women.

During pregnancy, metabolism and breathing rates increase, releasing more heat and carbon dioxide.

“There’s a little furnace inside your body that keeps you warm,” explains Professor Steve Lindsay, a public health entomologist at Durham University.

People who exercise are also on mosquitoes’ preferred list since exercise increases carbon dioxide emission, body heat, and sweating.

Taller individuals often emit more heat and carbon dioxide, which makes them more appealing to mosquitoes.

When mosquitoes get close, they decide whom to bite based on odors emitted by skin and breath.

“Odor plays the primary role,” says Lindsay. “Small, fast-flying chemical compounds create diversity. Mosquitoes live in a chemically charged environment.”

Other scientists like Lindsay also refute the idea that “sweet blood” attracts mosquitoes more. Instead, they explain that skin odor is the real attractant.

Microorganisms on our skin convert carbohydrates, fatty acids, and peptides into volatile organic compounds (VOCs).

These VOCs disperse into the air, and mosquitoes can differentiate them. Our skin contains over 500 VOCs.

Mosquitoes are also attracted to ammonia and lactic acid on skin; when combined with carboxylic acids, our skin becomes even more enticing to them.

Researchers at Rockefeller University studied skin odors from 64 individuals using nylon sleeves worn for six hours.

Their findings showed people with higher carboxylic acid levels were more attractive to mosquitoes.

The study found up to a 100-fold difference in attractiveness between the most and least appealing individuals, differences that persist for years.

“Your attractiveness to mosquitoes is largely stable over time,” says Lindsay.

People react differently when bitten by mosquitoes.

A genome-wide study has shown that genes involved in our immune system can influence how we respond to mosquito bites.

Interestingly, these genes are also associated with allergic reactions.

The size of the bite and how easily it breaks the skin can cause strong immune responses, which may make you more attractive to mosquitoes.

“Some feel they get bitten more because they have stronger reactions,” says Professor Heather Ferguson of Glasgow University’s medical entomology department. “Others might be bitten often but show little reaction.”

Biologically, some of us are simply easier targets for mosquitoes.

Ferguson adds: “It’s impossible to completely evade mosquito radar, so protecting yourself remains essential even if you don’t often get bitten.”

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