Contempt is never wise in biology. The creature that you look down on as lowly, degenerate, or disgusting may actually turn out to be sophisticated, successful, and–in some cases–waiting to tell you a lot about yourself. That’s certainly the case for lice.

The human body louse, Pediculus humanus, has two ways of making a living–either dwelling on the scalp, feeding on blood, or snuggling into our clothes and come out once or twice a day to graze on our bodies. For lice, we humans are the world. They cannot live for more than a few hours away from our bodies.Only by crawling from one host to the next does their species escape extinction.

A group of louse specialists recently decided to find