7 Reasons Mosquitoes Bite Some People More Than Others

Are you a magnet for mosquitoes? Understanding what lures the insidious insects can be useful in avoiding them.

Zika, West Nile, Malaria, Dengue ... the disconcerting catalog of illnesses spread by the flying disease-delivery vehicles known as mosquitoes is an ever-expanding thing. And along with vector-borne diseases, mosquitoes and their diabolic hypodermic mouthparts offer no shortage of itchy welts, meanwhile, their crazy-making hum can keep the soundest of sleepers swatting at their faces all night.

Do you make mosquitoes swoon? Some people seem to almost never, while others won the mosquito lottery – they don’t want to have anything to do with me. Others aren’t so lucky. Studies show that around 20 percent of people are especially irresistible. “High attractor types” is what Jonathan Day, a professor emeritus of Surveillance and Epidemiology at the University of Florida in Vero Beach, calls the unfortunate group.

Day says that the two most compelling factors of mosquito attraction have to do with sight and smell – which seems obvious, but it’s not a given that the mysteries of mosquitoes would be clear. There are all kinds of myths about what attracts and repels – for example, vitamin B-12 does not actually repel them – but scientists think the following factors likely do come into play. Some of these we can't do much about, but anything to help avoid the pests and reduce the use of dicey chemicals is worth the effort.

1. Apparel

As mentioned above, mosquitoes actually use their eyes to target victims. Jay explains that mosquitoes are highly visual, “especially later in the afternoon, and their first mode of search for humans is through vision.” Research shows wearing dark colors (green, black, and red) makes you easier to spot. (Note to self: Check camouflage summer wear.)

2. Blood Type

It’s all about the blood for mosquitoes; well that and nectar. Adult mosquitoes survive on nectar for nourishment, but females rely on the protein in our blood for the production of eggs. So it’s little surprise that some blood types may be more desirable than others. Research has found, in fact, that people with Type O blood are found to be almost twice as attractive to mosquitoes than those with Type A blood; Type B people were in the middle. In addition, 87 percent of people produce a secretion that signals what blood type they are; mosquitoes are drawn to those 87 percent more than the non-secretors, regardless of blood type.

3. Gas

Mosquitoes can sense carbon dioxide from a significant distance, and they can see human from a distance of 5-15 meters. These two cues help them track you down. The more one exhales, the more attractive they become. Larger people exhale more. Also to note, since human beings exhale carbon dioxide through the nose and mouth, mosquitoes are attracted to our heads, which explains the whole “mosquitoes buzzing about the ears all night” misery.

4. Heat and Sweat

Mosquitoes apparently have a nose for other scents besides carbon dioxide; they can sniff down victims through lactic acid, ammonia, and other compounds emitted in sweat. They also like people who run warmer; a hot sweaty human must seem quite delicious to them – couch potatoes, rejoice. Strenuous exercise increases the buildup of lactic acid and heat in your body, while genetic factors impact the amount of other substances naturally released by each person, making it easier for mosquitoes to find some people than others.

5. Lively Skin

Some research has shown that the types and amount of bacteria on one’s skin can play a role in bringing on the mosquitoes as well. Our dermal casing is naturally teeming with microscopic life, and the whole shebang mixed with our sweat creates a distinct fragrance. In one study, a group of men was divided into those who were highly attractive to mosquitoes and those who were not. The delicious ones had more of certain microbes on their skin than the unattractive ones, but fewer types – a larger community but less diverse. The bacteria factor could also explain why some mosquitoes are drawn to ankles and feet, an especially ripe source of bacteria.

6. Pregnancy

Women with a bun in the oven are probably those least wanting to attract mosquitoes, but alas, some species are evidently more attracted to pregnant women than women who are not. One study in Africa found that two times as many mosquitoes gravitated towards pregnant women as to non-pregnant women. Researchers believe it is due to an increase in exhaled carbon dioxide – they found that women in late pregnancy exhaled 21 percent greater volume of breath than non-pregnant women. They also discovered that the abdomens of pregnant women were 0.7°C hotter, adding to the mosquitoes-like-warm-bodies component.

7. Beer

Who knew mosquitoes had a taste for beer? In one study researchers found that significantly more mosquitoes landed on study participants after drinking a 12-ounce beer than before. However, the reason for this increase remains unclear, as neither ethanol content in sweat nor skin temperature showed any correlation between alcohol consumption and mosquito landings. Clearly the crafty pests aren't targeting inebriated folks as easy marks, but the findings do suggest that you should take precautions against mosquitoes when drinking alcohol.

Do mosquitoes love you? Have you found good ways to keep them away?