Study says mosquitoes attracted to body heat, carbon dioxide

Mosquitoes find some people tastier than others. But a widespread notion is that women, to mosquitoes at least, are the sweeter sex, supposedly because estrogen is a strong attractant.

In reality, gender does play a role, but not in the way most people think. As one report in the Annals of Internal Medicine pointed out, men are more likely to be attacked, primarily because of their greater body size.

“Larger persons tend to attract more mosquitoes,” the study said, “perhaps because of their greater relative heat or carbon dioxide.”

A similar effect can be seen among women. When scientists compared pregnant women with their nonpregnant counterparts in a Lancet study in 2000, they found that the pregnant women attracted twice as many mosquitoes. The study noted that the pregnant women exhaled more carbon dioxide and had higher body temperatures, allowing mosquitoes to detect them more easily.

In addition to carbon dioxide, lactic acid is strong attractant, which is why people are attacked more when they are outside and sweating, said Dr. Clifford W. Bassett of Allergy and Asthma Care of New York.

Bassett said mosquitoes can sense those chemicals off the skin from up to about 100 feet away.