…that bacteria on your skin produce.
A group of researchers made volunteers sleep in an enclosure connected to a mosquito enclosure. They tracked who the mozzies flew to and then did the sciencing, and they found out carboxylic acid odors are yummy for mosquitoes.
Kudos to the volunteers who sacrificed themselves for science.
This is creepy but important. Mosquitoes are not just a mere nuisance. They kill half a million people every year. Thanks to this study it would help us in designing better mosquito repellents. And kudos to those volunteers indeed (and their brave skin). Hopefully we can find a less itchy way for such studies! 
did you hear they’re genetically engineering male mosquitoes to be sterile and releasing them in the wild so that they can reduce the population of mosquitos? this felt very dystopian to me…but also, what a relief to have fewer disease causing mosquitos.