There are thousands of demodex mites on your face right now, and at night they come out to have sex.
Your body harbors at least two closely-related species of mites: Demodex folliculorum and Demodex brevis. Both live in your hair follicles, but folliculorum live in the follicles' main cavity, whereas the smaller brevis live in something called the sebaceous gland, which secretes a waxy oil called sebum — likely the mites' main food source.
Both types of Demodex are densest on the face — especially near the nose, eyebrows, eyelashes, and hairline — but they live anywhere on your body where hair follices are. Scientists, however, have never fully studied the total abundance of mites on the human body. Dan Fergus, a researcher that works with [Holly] Menninger, estimates that the average person has between 1.5 and 2.5 million mites, but no one really knows