Mosquitoes are blood-sucking insects that are attracted to moisture, sweat, heat, and carbon dioxide and are attracted to some people more than others. Mosquitoes most often feed from dusk to dawn.
Mosquitoes carry disease in some parts of the world. They are carriers of the West Nile virus and may transmit the virus to humans and animals. West Nile virus causes an infection that can lead to inflammation of the brain (encephalitis) or the tissues surrounding it and the spinal cord (meningitis). Mosquitoes in Africa as well as other parts of the world may carry malaria or yellow fever. Mosquitoes do not carry the human immunodeficiency virus (HIV).
Symptoms of a mosquito bite may last for hours, days, or even weeks. Common symptoms that begin immediately are:
- Reddened skin.
- A swollen lump (wheal).
Staying indoors at dawn and dusk and in the early evening, coupled with wearing long-sleeved shirts and long pants when outdoors, may lower the risk for mosquito bites. Insect repellent, applied sparingly to skin and sprayed on clothing, may keep mosquitoes away.
Why do Mosquitoes Like Me Best?
Although researchers have yet to pinpoint what mosquitoes consider an ideal hunk of human flesh, the hunt is on. "There's a tremendous amount of research being conducted on what compounds and odors people exude that might be attractive to mosquitoes," says Joe Conlon, PhD, technical advisor to the American Mosquito Control Association. With 400 different compounds to examine, it's an extremely laborious process. "Researchers are just beginning to scratch the surface," he says.
Scientists do know that genetics account for a whopping 85% of our susceptibility to mosquito bites. They've also identified certain elements of our body chemistry that, when found in excess on the skin's surface, make mosquitoes swarm closer.
- "People with high concentrations of steroids or cholesterol on their skin surface attract mosquitoes," Butler tells WebMD. That doesn't necessarily mean that mosquitoes prey on people with higher overall levels of cholesterol, Butler explains. These people simply may be more efficient at processing cholesterol, the by-products of which remain on the skin's surface.
- Mosquitoes also target people who produce excess amounts of certain acids, such as uric acid, explains entomologist John Edman, PhD, spokesman for the Entomological Society of America. These substances can trigger mosquitoes' sense of smell, luring them to land on unsuspecting victims.
- But the process of attraction begins long before the landing. Mosquitoes can smell their dinner from an impressive distance of up to 50 meters, explains Edman. This doesn't bode well for people who emit large quantities of carbon dioxide.
- "Any type of carbon dioxide is attractive, even over a long distance," Conlon says. Larger people tend to give off more carbon dioxide, which is why mosquitoes typically prefer munching on adults to small children. Pregnant women are also at increased risk, as they produce a greater-than-normal amount of exhaled carbon dioxide. Movement and heat also attract mosquitoes.
So if you want to avoid an onslaught of mosquito bites at your next outdoor gathering, stake out a chaise lounge rather than a spot on the volleyball team. Here's why. As you run around the volleyball court, the mosquitoes sense your movement and head toward you. When you pant from exertion, the smell of carbon dioxide from your heavy breathing draws them closer. So does the lactic acid from your sweat glands. And then -- gotcha.
With a long track record -- mosquitoes have been around for 170 million years -- and more than 175 known species in the U.S., these shrewd summertime pests clearly aren't going to disappear any time soon. But you can minimize their impact.