Question Why do mosquitoes bite me and not my friend?
Answer
Recent evidence suggests that some people give off masking odors that prevent mosquitoes from finding them.

Scientists have been studying what attracts and repels mosquitos for a long time. This is important because mosquito bites are more than just itchy. Mosquitoes are carriers for a host of diseases, including malaria, yellow fever, West Nile virus, and Dengue fever.

Researchers have come up with some creative ways to study mosquito preferences. At Rothamsted Research in the UK, James Logan and John Pickett (Vince, 2006) devised some unique ways of testing body odor and found chemicals that smell bad to mosquitoes. First, they had two different people put one hand into each end of a chamber and the investigators watched which hand the mosquitoes preferred. Then they selected the person who was not preferred (who felt lucky up to this point) and sealed their body in foil to collect their sweat. Talk about an unpleasant experiment. The researchers set about analyzing the body chemicals and are hoping to use them to make an insect repellent.

The female mosquito is the one that bites (males feed on flower nectar). She requires blood to produce eggs. Her mouthparts are constructed so that they pierce the skin, literally sucking the blood out. Her saliva lubricates the opening. It’s the saliva plus the injury to the skin that creates the stinging and irritation we associate with mosquito bites.

There are hundreds of species of mosquitoes belonging to the family Culicidae. Since they breed in standing water, a way to eliminate them around the home is to remove objects where water collects, such as cans, buckets, old tires, and refreshing the water in bird baths at least once a week. Turn water barrels upside down during the winter, as well.
Insect repellents often contain DEET (N,N-diethyl-meta-toluamide) although there are other options that have been registered by the Environmental Protection Agency, such as picaridin and oil of lemon eucalyptus.
You can try to limit your exposure to mosquitoes when outdoors by using a fan or by covering exposed skin with light colored clothing and a hat. Mosquitoes tend to be more of a problem from dusk to dawn.

Published: 11/19/2019. Updated 1/14/2025. Author: Science Reference Section, Library of Congress