Why mosquitoes attack some people and ignore others? Science has the answer

Mosquitoes are very annoying, and I hate being attacked by them. Researchers have determined that blood type isn’t the lure some have thought, but rather the scent profile of certain carboxylic acids in our skin.

I hate being bitten in my sleep, only to wake up with some horrible itchy bite.

Scientific American:

The researchers analyzed the subjects’ scent profiles to see what might account for this huge difference. They found a pattern: the most attractive subjects tended to produce greater levels of carboxylic acids from their skin while the least attractive subjects produced much less.

Carboxylic acids are common organic compounds. Humans produce them in our sebum, the oily layer that covers our skin; There, the acids help keep our skin moisturized and protected, says Bhoshal. Humans excrete much more carboxylic acids than most animals, adds de Obaldia, although the amount varies from person to person. The new study had too few participants to determine which personal characteristics predispose someone to produce high levels of carboxylic acids — and there’s no easy way to test your own skin’s carboxylic acid levels outside of a laboratory, Voshal said. (However, he thinks that sending people skin swabs in the mail could make for an interesting citizen science project in the future.)

But we do know that skin maintains a relatively constant level of carboxylic acids over time. This, in turn, leads to a consistent flavor profile. (Mosquitoes may also be attracted to skin bacteria by digesting the carboxylic acids we produce, Vosshall suggests.) When Vosshall and De Obaldia ran their tournament multiple times over a period of several months, they found that human attraction rankings were largely the same. Any individual factors that may have varied during these months – from what each subject ate to the type of soap they used – did not seem to make a difference.

“This property of being a mosquito magnet stays with you for life—which is either good news or bad news, depending on who you are,” says Voshal.