Why mosquitoes are attracted to humans

Anyone who has suffered through the pain and irritation of mosquito bites knows what troublesome pests mosquitoes can be. But what attracts mosquitoes to humans in the first place? Why is it that some people seem almost completely immune to these little buggers? Why, in a crowd, do mosquitoes tend to be partial to one victim over another?

The explanation, as it turns out, is both simple and complex, and requires a thorough understanding of mosquito behavior. When you know how mosquitoes are attracted to you, you can better prevent their painful, itchy bites.

Why do mosquitoes bite?

Only female mosquitoes bite. They’ve evolved a proboscis, a long, tubular mouth, not unlike that seen on butterflies that can puncture the skin and suck blood. They seek to feed on blood to get the nutrients required to produce eggs. A male mosquito’s primary role is reproduction.

What are mosquitoes attracted to?

Mosquitoes are attracted to moist areas to breed and produce eggs. That's why it’s very important to prevent standing water in your yard and other areas around your home.

What attracts mosquitoes to humans?

  • Your blood. As previously mentioned, female mosquitoes feed on blood in order to provide nutrients to their eggs.

  • Your breath. In addition to a proboscis that can puncture human skin, female mosquitoes sport long antennae and olfactory (odor-sensing) organs called palps. These instruments are attuned to the odor of carbon dioxide, or CO2, which we produce every time we exhale. High concentrations of CO2, which mosquitoes can detect from more than 150 feet away, offer an initial temptation to hungry mosquitoes. However, CO2 isn’t the only determinant of who gets bitten, and how badly.

  • Your smell. Entomologists at the University of California, Riverside, have determined that certain odors released via perspiration are more likely to attract mosquitos. Substances such as uric acid, lactic acid and ammonia can also be released by bacteria that live in human skin. And, the higher your body temperature, the more likely you are to sweat. These facts help to account for why mosquito bites will frequently be clustered around the feet, ankles, wrists and hands, as all these areas of the body tend to be exposed to the elements, to collect and retain moisture and to play host to larger bacterial colonies.

  • Reasons completely beyond your control. There is no single determining factor explaining why mosquitoes bite who they bite. Researchers in Japan have demonstrated that individuals with Type O blood are more likely to be bitten than individuals with Type A blood. Your metabolism, with its capacity to raise and lower your body temperature, is a factor as well. Scientists have established that an individual’s genetic make-up can account for 85 percent of the various factors that make them a “mosquito magnet.”

When do mosquitoes feed?

Mosquitoes are most active during the hours of sunset and sunrise, but there are day biters, too.

Do mosquitoes bite other species?

Human beings aren’t alone in dealing with mosquitoes. Certain species of mosquito attack birds, others mammals and some even selectively target fish and reptiles. However, in situations where a given species’ preferred food supply is low or threatened, the mosquito will not hesitate to be opportunistic and feed on whatever it can.

Regardless of whether mosquitoes have a taste for you or not, they’re more than a nuisance. They are a risk to public health wherever they thrive and are responsible for the spread of such deadly diseases as malaria, dengue fever and the West Nile virus, as well as the newly prominent Zika virus. If you’re concerned about medical symptoms associated with any of these conditions and suspect that they may be a result of a mosquito bite, consult your physician.