Why Do Mosquitoes Bite Some People More Than Others?
The short answer
- It’s mostly your skin. People with more of certain skin acids attract far more mosquitoes, and it doesn’t change over time.
- It’s largely inherited. A twin study put about 62% of the difference down to genes.
- Pregnancy, a few drinks and dark clothing make you easier to find. Garlic and vitamin B change nothing.
- A repellent on your skin and a fan where you sit are what work.
Everyone knows a mosquito magnet. Often it’s the person who asks about Notch, because they’ve been told for years that it’s all in their head, and it isn’t.
The science on this is more specific than most people expect, so here it is, start to finish: how a mosquito finds you, why it picks you over the person next to you, and what actually helps.
How they find you
A mosquito doesn’t see a person from across the yard. It follows a chain of clues, each one taking over as it gets closer.
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From across the yardYour breath
The carbon dioxide you breathe out is the first clue, and they fly upwind along it. Smelling it also switches on their eyes: in a 2022 study, mosquitoes ignored colored objects until they caught a whiff, then headed for red, orange, black and human skin tones.1
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A couple of feet outYour heat
A dark shape against the sky, and the warmth coming off it. Mosquitoes can sense the heat of skin from about two feet away, but only when breath and skin scent are already in the air.2 Heat alone barely registers.
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On landingYour skin
Bacteria on your skin turn its oils and sweat into hundreds of compounds, and some of those are what mosquitoes are really after. This is where people differ most, and no amount of holding your breath or changing your shirt alters it.
Why it picks you
100×
The most attractive of 64 volunteers drew more than 100 times as many mosquitoes as the least attractive, and stayed a magnet over several years of retesting.
De Obaldia 2022, Cell3
62%
How much of the difference between people comes down to genes, by a study of identical and non-identical twins. That’s in the same range as height.
Fernández-Grandon 2015, PLOS ONE4
The 2022 study pinned the difference on carboxylic acids, a family of fatty acids on the skin. The biggest mosquito magnets had much higher levels of them, and the ranking barely moved over years of retesting.3 The twin study says where those levels come from: mostly your parents.4 If you’ve been the one getting bitten since you were a kid, that’s why.
What makes it worse, and what doesn’t
None of these turn a non-magnet into a magnet. The first three make you a little easier to find. The last three are folklore.
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Adds to itPregnancy
About twice as many mosquitoes in a 2000 study. Pregnant women breathe out about 21% more air and run slightly warmer: more breath, more heat.5
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Adds to itDrinking alcohol
Studies have found more mosquitoes land on people after they drink.6
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Adds to itDark clothing
Once they’ve smelled your breath, dark and red-orange colors draw their eye.1,6 Skin tone doesn’t: every tone tested drew similar attention.1
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MythEating garlic
Tested, and it didn’t make people less attractive to mosquitoes.6
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MythTaking vitamin B
Same result. Studies that tested it found no change in how many mosquitoes came.6
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MythSkipping perfume
There’s no evidence that scented lotions or perfume draw more mosquitoes.6 It’s your skin they smell, not your fragrance.
What helps
You can’t change your skin chemistry or your genes. You can break the chain of clues.
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Cover the skin
A repellent on every bit of exposed skin works at the last stage, the one that makes you a magnet in the first place. Reapply as the label directs.
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Sit in the breeze
Mosquitoes are weak fliers, and a fan scatters the plume of breath and scent they follow in on.
How fans keep mosquitoes away on BugRepellent.Guide
BugRepellent.Guide is a repellent research site run by the Notch team.
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Wear lighter colors at dusk
It won’t hide you, but it gives them less to aim at once they’ve caught your scent.
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Dump standing water
Once a week, nearby, so fewer mosquitoes hatch close to where you sit.
A repellent for the mosquito magnets
We made Notch Nourish + Defend Botanical Insect Repellent for exactly the person who always gets bitten first. It’s a 5% geraniol lotion that goes on like skincare, so it’s easy to cover every bit of exposed skin, and it has a soft, rosy scent. It repels mosquitoes and ticks, and for maximum protection, you reapply every hour.
Frequently asked questions
Can you stop being a mosquito magnet?
Not really. Your natural attractiveness stays stable for years. But a repellent on exposed skin, a fan where you sit and lighter clothing make you much harder to bite, which is what matters.
Do mosquitoes prefer certain skin tones?
No. In the 2022 color study, all the skin tones tested drew similar attention. Clothing color mattered more than skin color.
References
- Alonso San Alberto D, et al. The olfactory gating of visual preferences to human skin and visible spectra in mosquitoes. Nature Communications, 2022.
- Chandel A, et al. Thermal infrared directs host-seeking behaviour in Aedes aegypti mosquitoes. Nature, 2024.
- De Obaldia ME, et al. Differential mosquito attraction to humans is associated with skin-derived carboxylic acid levels. Cell, 2022.
- Fernández-Grandon GM, et al. Heritability of attractiveness to mosquitoes. PLOS ONE, 2015.
- Lindsay S, et al. Effect of pregnancy on exposure to malaria mosquitoes. The Lancet, 2000. Summary from Down To Earth.
- University of Wisconsin–Madison. Preventing mosquito bites: home remedies.
