Demodex folliculorum are eight-legged mites measuring 0.01-inch-long and inhabit almost all human beings. The mites live on the nipples and sometimes lips and eyelashes hence bearing the name face mites.
On sequencing a mite's genome for the first time, researchers from the University of Reading found that inbreeding is making the parasites to shed unnecessary genes. The mites are also losing their ability to secrete a compound dubbed melatonin. The compound which exists in humans, makes invertebrates active at night and fuels their mating sessions. Mites are thus likely to mate on humans while they sleep.