If you’ve ever enjoyed a hike in the woods or spent a warm weather day outdoors only to come home covered in mosquito bites, you probably wonder why you were a human target for the pests when others around you didn’t get a single bite.
Though mosquito bites are frequently harmless, only causing minor irritation, redness, and itchiness, some mosquitoes can actually transmit potentially deadly diseases when they bite, including Zika, malaria, yellow fever, dengue, Chikungunya, and West Nile virus, so you’ll want to avoid getting bitten as much as you possibly can.
But you’re likely also wondering why mosquitoes bite you more than other people you’ve been outside with, and it has nothing to do with some people having sweeter blood than others, despite what well-meaning sympathizers might have told you.
Jonathan Day, a professor of medical entomology at the University of Florida, explained to NBC News that there are two main reasons why some people are mosquito magnets, and they involve sight and smell.
Day explained that mosquitoes are “highly visual,” especially in the late afternoon hours, so they go for what they can easily see. So if you’re wearing dark colors, including blue, red, or black, you’ll be a brightly colored target for flying pests.
Also, if you’re moving around, you’re easier for them to spot, explained Day. This is especially problematic if you’re enjoying outdoor exercise, like hiking, biking, or swimming, but can certainly be a problem even if you’re just relaxing with pals in the warm weather.
The good news is, you don’t have to sit frozen in the same spot to avoid being attacked. Day recommends wearing lightweight, breathable fabrics in light colors when you’re outside and covering up as much as is reasonably possible.
But while you can take measures to help prevent mosquitoes from seeing you, it seems they might be able to sense you based on your unique personal scent, which is largely unavoidable.
As Day told TIME magazine, “Some people produce more of certain chemicals in their skin. And a few of those chemicals, like lactic acid, attract mosquitoes.” Lactic acid is given off in your sweat when you exercise, according to Day, and mosquitoes are also attracted to acetone, a chemical released in your breath, and estradiol, a breakdown product of estrogen. If you have elevated levels of these chemicals, you might notice more mosquito bites than the people around you.
Day explained that your blood type might also have something to do with it because people with type O blood are more susceptible to pest bites than A and B … and unfortunately, you can’t swap your blood type.
Another genetic factor that might determine mosquitoes’ attractiveness to you is your metabolic rate, or the amount of carbon dioxide that your body releases as you burn energy. The higher your metabolic rate, the more carbon dioxide you produce, and the easier it is for mosquitoes to hone in on you.
This effect is compounded when you’re exercising because movement raises your metabolic rate and the level of lactic acid you release, plus you’re easier to spot when you’re in motion, making those outdoors workouts especially miserable for some of us. Additionally, the higher your body temperature, the more attractive you are to pests.
“Pregnant women and overweight or obese people tend to have higher resting metabolic rates, which may make them more attractive to mosquitoes,” said Day, who also told TIME that drinking alcohol is a major culprit for winged pests, too — all factors that increase your core body temperature, thus increasing the amount of warmth you give off.
All of these factors make up your unique body chemistry, which helps determine how attractive you are to the little buggers.
Wearing fruity, floral scents certainly won’t help matters, because most fragrances will only add to the pests’ attraction. That is unless you wear Victoria’s Secret Bombshell Eau de Parfum, which was determined in 2016 to repel mosquitoes as well as some of the top mosquito repellents on the market. Who knew!?
As for how to find the best insect repellent, Day recommends something with at least 15% DEET, a chemical which helps ward off many of the most annoying insects, including mosquitoes. He told TIME that you’ll want to “spray it into your hands and then rub it on your skin to avoid inhaling it,” providing protection for about 90 minutes.
Mosquitoes tend to feed around dawn and dusk when humidity levels are highest but winds are calm because they can’t fly in breezes of more than 1 mile per hour. So if you are outside in those times, you can also point a fan near you to increase wind speed and lure them away.
If you’re hoping to avoid mosquito bites, your best bet is to stay inside during prime mosquito time. But there’s nothing wrong with enjoying the great outdoors as long as you pick a bug spray you like, cover up as much as you can, and hope for the best.
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