5 Unexpected Reasons You Get So Many Mosquito Bites: Blood Type, Clothes, and More

While summer is by far my favorite season, fall is a close second. The milder temperatures and lower humidity mean I can spend more time outside doing things I love: walking, hiking, and spending time at the lake. But that time in nature quickly turns sour when I find myself covered in red, itchy bumps after spending just a few minutes outdoors. Because even though autumn is almost here, the pesky mosquitoes are still active until the beginning of November.

If you’re like me, you get frustrated with the amount of mosquito bites that pop up all over your body and make you want to scratch the skin around the bite to the bone. While the bites themselves can be annoying, it’s downright infuriating when I walk inside sporting several bright red holes while my friends report that they don’t have any.

Why that? Not that we are particularly unlucky. There are actually scientific reasons why mosquitoes attract certain people. Here’s exactly why mosquitoes bite and how you can make yourself less of a target this season and beyond. (You can also find out how to easily remove ticks without tweezers.)

Why do mosquitoes bite?

Contrary to what you might think, mosquitoes don’t bite people for food, they feed on plant nectar. Only female mosquitoes bite, and they do so to receive the blood proteins needed to develop their eggs.

Why are some people more prone to bites?

There are several factors that affect why some people are more prone to mosquito bites than others:

blood group

A common belief is that mosquitoes are attracted to certain things blood type, considering that mosquitoes bite humans for their blood. Blood type is determined by genetics, and each blood type is created from the different sets of specific proteins, called antigens, on the surface of red blood cells. There are four main blood types: A, B, AB and O.

Although there are no firm conclusions about which blood type is more attractive to mosquitoes, several studies have suggested that people with type O are more appetizing to mosquitoes. A 2019 study looked at the feeding behavior of mosquitoes when presented with samples of different blood types and found mosquitoes fed on the type O diet more than any other. A 2004 study also found that mosquitoes land on blood type O secretors (83.3%) significantly more than type A secretors (46.5%).

However, these studies are not definitive, and much is still up in the air about mosquitoes’ blood type preferences.

Color of clothes

Mosquitoes are very visual hunters when it comes to finding a human to bite. This means that movement and dark clothing colors like black, navy and red can stand out to a mosquito. Research has shown that mosquitoes are more attracted to the color black, but there has been little further research into why this is so.

Carbon dioxide

Mosquitoes use sight and smell to find hosts to bite. One of the fastest ways mosquitoes can smell a person is through the carbon dioxide emitted when we breathe. According to research published in the journal Chemical Senses, mosquitoes use an organ called a maxillary palp to detect carbon dioxide and can detect it from 164 feet away.

Because carbon dioxide is a big attractant, people who emit more carbon dioxide (older people and people who breathe heavily when they exercise) are more attractive to a mosquito.

Body odor and sweat

Mosquitoes are attracted to more substances and compounds than just carbon dioxide. Mosquitoes can find people to bite by smelling substances present in human skin and sweat, such as lactic acid, uric acid and ammonia.

Researchers are still learning why certain body odors are more attractive to mosquitoes, but they know that genetics, skin bacteria and exercise play a big factor. Genetics affect the amount of uric acid released, while exercise increases the build-up of lactic acid.


In a small study, it was observed that mosquitoes landed on participants more often after drinking a small amount of beer. But before you swear off beer forever, know that the study only had 14 participants and found that mosquitoes may be only slightly more attracted to people who have drunk beer.

The size and severity of a bite is related to how your immune system responds to the saliva introduced by the mosquito when it bites.

Suriyawut Suriya/EyeEm/Getty Images

Why do some people get more swollen from mosquito bites than others?

Mosquito bites can vary in size from small spots to large ones. Why is this the case?

Bites affect people differently. The size and severity of a bite is related to how your immune system responds to the saliva introduced by the mosquito when it bites. When mosquitoes bite, they inject some saliva when drawing blood. This saliva contains certain anticoagulants and proteins, which cause the immune system to respond to these foreign substances.

Our body responds by releasing histamine, a chemical that is released by white blood cells when the immune system fights allergens, which causes the itch and inflammation of the bite.

Prevention and treatment of mosquito bites

The best way to handle a mosquito bite is to not get them in the first place, but that’s often easier said than done.

Some common ways to prevent mosquito bites include:

  • Use repellents and insect sprays (Repel, Off! Deep Woods and other brands that contain DEET)
  • Use natural repellants (citronella essential oilneem oil, thyme essential oil)
  • Avoid going outside at dawn or dusk
  • Avoid dark-colored clothing, especially black
  • Avoid standing water and try to eliminate standing water near your home
  • Use mosquito nets when camping or sleeping outdoors
various types of bug spray lined up on a table

Repellents are very effective in preventing mosquito bites.

Amanda Capritto/CNET

Mosquito bites, while annoying, are often not serious and will resolve within a few days. In the meantime, there are several treatments to relieve itching and inflammation:

  • Clean with alcohol if it is a fresh bite
  • Take an oatmeal bath
  • Use over-the-counter antihistamines such as Benadryl or Claritin
  • Apply mild corticosteroid creams
  • Use aloe vera to reduce inflammation
  • Try a cold compress

Although it is difficult, try your best not to bite the bite too much to avoid any kind of skin reaction or infection.

For more information, read about the five smart ways to repel mosquitoes this summer, the mosquito forecasting tool launched by Google and Off, and how you can make your own DIY traps for mosquitoes, hornets and other flying pests.

The information contained in this article is for educational and informational purposes only and is not intended as medical or health advice. Always consult a doctor or other qualified health care provider with any questions you have about a medical condition or health goals.

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