They won’t suck just anyone’s blood, you know

Hey there, time traveller!
This article was published 29/07/2013 (4462 days ago), so information in it may no longer be current.

MOSQUITO season is in full swing. A lucky few people seem immune to the bites of the pesky insects. Others can’t seem to avoid them.

New research explains mosquitoes’ apparent selectivity. According to an article in Smithsonian magazine, an estimated 20 per cent of people are “especially delicious” to mosquitoes. They are bitten more often than others.

Why? A number of factors are at play. Chief among them is blood type. “Not surprisingly — since, after all, mosquitoes bite us to harvest proteins from our blood — research shows that they find certain blood types more appetizing than others,” the article reports. Type O is at the top of the list. Additionally, about 85 per cent of people secrete a chemical signal that indicates their blood type. These “secretors” are more prone to bites regardless of their blood type.

Another factor is the amount of carbon dioxide people emit when they breathe. Larger people exhale more of the gas, which may explain why adults tend to get bitten more often than children. This also means obese people are more prone to getting bitten than average or underweight people. Sweat, high body temperatures and skin bacteria also play a role. Pregnancy, which increases body temperature and carbon dioxide emission, may also increase the likelihood of bites.

And if you’re enjoying a beer at a barbecue, you may have made yourself a mosquito target. No one has been able to pinpoint why drinking beer makes people more attractive to mosquitoes. Some have theorized the elevation in body temperature and the amount of ethanol in sweat may play a role, but neither theory has panned out.

— Washington Post