What's got eight legs, lives on you, is invisible to the naked eye, eats the grease on your skin, and does unspeakable things on your face while you're sleeping?!
Give up?! Well tiny microscopic face mites called demodex have been living on us humans for centuries.
They come from the arthropod family, the same as insects, spiders and crustaceans, and are closely related to the tick. And if you think their eating and mating habits sound gross, you should try looking at them under a microscope!
By examining the populations of these mites and how they vary across different countries, Megan Thoemmes of North Carolina State University is trying to unlock some of the secrets about how humans migrated around the planet.
Images: USDA. Confocal and Electron Microcopy Unit.