If you’re the person who always ends up covered in mosquito bites while your friends remain untouched, you’re not imagining things — mosquitoes do have favorites.
For years, scientists have studied what makes certain people more appetizing to mosquitoes, and the answer lies in a complex mix of body chemistry, biology, and behavior.
According to Danish broadcaster DR, new findings shed light on exactly why some of us are mosquito magnets — and how to finally get a break from the bites.
It’s Not You — It’s Your Breath (and Size)
One of the biggest factors that draws mosquitoes is carbon dioxide (CO₂) — the gas we all exhale. And the more you breathe out, the more mosquitoes notice you.
“Mosquitoes use the carbon dioxide in exhaled air to locate large mammals like humans,” explains Lars Brøndum, biologist at the Natural History Museum in Aarhus. “The larger a person is, the more CO₂ they exhale. This could mean that larger people tend to be bitten more often.”
So yes — your size may literally be working against you in mosquito season.
Sweat and Body Odor Play a Big Role
It’s not just about breathing.
If you’ve just gone for a jog or been outside in the sun, your body is giving off another mosquito lure: heat.
According to Thomas Pape, an entomologist at the Natural History Museum in Denmark, body warmth and sweat both increase your risk of being bitten. That’s because mosquitoes are drawn to lactic acid and other chemicals released through the skin after physical activity.
In short: exercise might be great for your health, but it’s not winning you any points with mosquitoes.
Skin Bacteria and Blood Type Matters — A Lot
A surprising study from the Netherlands revealed that people with a more diverse bacterial flora on their skin were bitten less often.
While scientists aren’t yet sure how or why this works, it suggests that the unique microbial balance on your skin could make you either a mosquito magnet or a mosquito repellent.
If you’re blood type O, you might also want to invest in some extra bug spray.
A Japanese study involving 64 participants found that people with blood group O were significantly more attractive to mosquitoes than those with blood types A, B, or AB. The biggest difference was between blood types O and A, suggesting that mosquitoes can somehow detect — and prefer — certain blood types.
This doesn’t mean you can change your blood type, of course, but it does explain why two people sitting side by side can have very different bite counts.
So... What You Can Actually Do About It
Unfortunately, you can’t control your blood type or instantly change your skin bacteria. But you can take practical steps to reduce your mosquito appeal:
Cover up: Long-sleeved clothing, tight wrist cuffs, and long pants tucked into socks can reduce exposed skin.
Stay cool: Avoid heavy physical activity if you're in a high-risk mosquito zone.
Use repellents: DEET-based repellents are still among the most effective.
Skip the perfume: Fragrances can act as an added attraction.
It may feel unfair to be the one mosquitoes always swarm toward, but science shows it’s more than bad luck — it’s biology. The good news? Knowing why you’re a target is the first step to doing something about it.
So next time you head outdoors, remember: it's not personal — it's chemical.
