The compound known as VUAA1 was borne of recent discoveries about the fundamental way that mosquitoes smell. Just a few years ago, it was thought that the basic sniffing mechanism for mosquitoes was very similar to that of mammals--that is, that odorant receptors (ORs) sitting atop nerve cells are tuned to different molecules, and when a receptor comes in contact with its target molecule it notifies the brain via the nerve.

 

But mosquitoes’ olfactory senses works a bit differently. It turns out their ORs rely on a sort of nerve switchboard, a co-receptor called Orco. When an OR detects an odorant molecule, it activates while the other ORs on a given antenna remain deactivated. The Orco acts as a sort of switch that tells the brain which OR is activated, and thus what molecule is being detected.