Scientists aren’t sure what microscopic face mites do, but they know where to find them: in the pores and hair follicles of most adult humans’ faces.
At this moment, hundreds or thousands of tiny eight-legged animals are nestled deep in the pores of our faces—my face, your face, your best friend’s face, and pretty much every other face you know or love. In some sense, they’re our closest companions.
These animals are mites—tiny arachnids, related to spiders and ticks. They’re too small to see with the naked eye, and too small to feel as they move about. Not that they move much: Face mites are the ultimate hermits, likely living most of their lives head down inside a single pore. In fact, their bodies are shaped like the inside of a pore, evolution having long ago reduced them to narrow plugs topped with eight absurdly tiny legs.
Face mites were first discovered in the human ear canal in 1841; soon thereafter they were found in the eyebrows and eyelashes. Since then, we’ve learned that they live not only among towering forests of brows and lashes but also in the savannas of short, fine hairs all over our bodies, save the palms and the bottoms of feet. The oil-producing pores in which those hairs sit are particularly dense on the face—as are the mites that live in them.
Perhaps more surprising, our pores are home to at least two different species of mites, both of the genus Demodex. The shorter and stubbier of the two is D. brevis; it’s shaped roughly like the kind of club a cartoon caveman might carry, and it prefers to nestle deeply into sebaceous glands. The other is D. folliculorum, which is longer and skinnier and hangs out in hair follicles, closer to the skin’s surface.