While summer is by far my favorite season, fall comes a close second. The moderate temperatures and lower humidity allow me to spend more time outside doing things I love: hiking, walking and spending time at the lake. But that time in nature is quickly spoiled when, after just a few minutes outdoors, I find myself covered in red, itchy bumps. Because although autumn is almost here, annoying mosquitoes are still active until the beginning of November.
If you’re like me, you get frustrated by the number of mosquito bites that appear all over your body, making you feel like scraping the skin around the bite until you reach the bone. While the bites alone can be annoying, it’s downright annoying when I come into the house with multiple new bright red welts while my friends are kind enough to report that they don’t have a single one.
Why is that? It’s not that we’re particularly unlucky. There are actually scientific reasons why mosquitoes single out certain people. Here’s exactly why mosquitoes bite and how to make yourself less of a target this season and beyond. (You can find out too how to remove ticks easily without tweezers.)
Why do mosquitoes bite?
Contrary to what you might think, mosquitoes don’t bite humans to eat – they feed on plant nectar. Only female mosquitoes bite, and they do so to obtain proteins from your blood that are necessary for the development of their eggs.
Why are some people more prone to bites?
There are several factors that influence why some people are more susceptible to mosquito bites than others:
blood type
A common belief is that mosquitoes are attracted to certain ones blood groups, considering that mosquitoes bite people for their blood. Blood type is determined by genetics, and each blood type is formed based on 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.
While there are no firm conclusions about which blood type is more attractive to mosquitoes, several studies have shown that people with blood type O are the most appetizing to mosquitoes. A 2019 study observed the feeding behavior of mosquitoes when presented with different blood type samples and found that mosquitoes were fed from the Type O feeder more than any other. A 2004 study also found that mosquitoes were significantly more likely to land on blood group O secretors (83.3%) than on group A secretors (46.5%).
However, these studies are not definitive, and much is still up in the air about mosquito preferences when it comes to blood type.
clothing color
Mosquitoes are very visual hunters when it comes to finding a human to bite. This means exercise and dark clothing colors like black, navy blue, and red can be noticeable to a mosquito. Research has shown that mosquitoes are more attracted to the color black, but there has been little additional research into why this is the case.
carbon dioxide
Mosquitoes use sight and smell to find hosts to bite. One of the quickest ways mosquitoes can sniff out a person is through the carbon dioxide released when they breathe. According to a study published in the journal Chemical Senses, mosquitoes use an organ called the maxillary palm to detect carbon dioxide and can sense it from 50 meters away.
Because carbon dioxide is a tremendous attractor, people who give off more of it — taller 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 humans to bite by smelling substances present on human skin and sweat, including lactic acid, uric acid, and ammonia.
Researchers are still learning why certain body odors are more attractive to mosquitoes, but they do know that genetics, bacteria on the skin, and exercise play a role. Genetics affect the amount of uric acid secreted, while exercise increases lactic acid build-up.
Beer
One small study observed that mosquitoes landed on participants more often after they drank a small amount of beer. But before you swear off beer for good, know that the study only had 14 participants, and mosquitoes may be only slightly more attracted to people who drank beer.

The size and severity of a bite depend on how your immune system responds to the saliva introduced by the mosquito when it bites.
Suriyawut Suriya/EyeEm/Getty Images
Why do some people swell more than others from mosquito bites?
Mosquito bites can range in size from small spots to large welts. Why is that?
Bites affect people differently. The size and severity of a bite depend on how your immune system responds to the saliva introduced by the mosquito when it bites. When mosquitoes bite, they inject some saliva while drawing blood. This saliva contains certain anticoagulants and proteins that trigger the immune system to react to these foreign substances.
Our bodies respond by releasing histamine — a chemical released by white blood cells when your immune system is fighting allergens — which causes the itching and inflammation of the bite.
Prevention and treatment of mosquito bites
The best way to deal with a mosquito bite is to avoid getting them in the first place — but often that’s easier said than done.
Some common ways to prevent mosquito bites are:
- Use repellents and bug sprays (Repel, Off! Deep Woods and other brands that contain DEET)
- Use natural repellents (Citronella volatile oilneem oil, thyme essential oil)
- Avoid going outside at dawn or dusk
- Avoid dark clothes, especially black ones
- Avoid standing water and try to eliminate standing water near your home
- Use mosquito nets when camping or sleeping outdoors

Repellents are highly effective in preventing mosquito bites.
Amanda Capritto/CNET
Mosquito bites, while annoying, are often not serious and go away in a few days. There are now several treatments to relieve itching and inflammation:
- Clean with rubbing alcohol when the bite is fresh
- Take an oatmeal bath
- Use over-the-counter antihistamines like Benadryl or Claritin
- Apply mild corticosteroid creams
- Use aloe vera to reduce inflammation
- Try a cold compress
Although it is difficult, try as best you can not to itch the bite too much to avoid skin reactions or infection.
Read more about the Five clever ways to repel mosquitoes this summer, the mosquito prediction tool started by google and off, and as 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 health or medical advice. Always consult a physician or other qualified healthcare provider with any questions about a medical condition or health goals.