Demodex folliculorum is a type of mite. It’s one of two types of Demodex mites, the other being Demodex brevis. This is also the most common type of Demodex mite.

D. folliculorum lives within the hair follicles on human skin, feeding on dead skin cells. Unlike D. brevis, this type is mostly found on the face. These mites tend to be most prevalent around the eyes, affecting the lids and lashes. When large numbers of D. folliculorum are found on humans, the infestation is known as demodicosis.

During the day, demodex folliculorum feed on dead skin cells, while at night they emerge to the surface to mate and lay eggs. Females lay between 20 and 24 eggs in a single follicle.
After they hatch it takes them seven days to mature into adults. Mites are usually between 0.1mm and 0.4mm long and are rarely harmful.

Demodex mites are usually acquired at birth and almost everyone has them on their skin; however, their density usually increases with age