There are 2 types of demodex mites. The long variety, Demodex Folliculorum, lives mainly in the hair root . And short variety, Demodex Brevis, lives mainly in sebaceous glands. The length of the mites range from about 0.1mm to 0.4mm. Demodex is a kind of parasitic mite which lives on human skin. It can live in the roots of hair or sebaceous glands anywhere on the body.
	Length is only thing that distinguishes the two type of Demodex. They have a similar system. They pierce the epidermis with a needle-like mouth organ through which they absorb feeding. After boring into the skin and establishing itself in a follicle or sebaceous gland, the parasitic mite will lay eggs and shed its skin three times. Female mites can lay about 50 eggs through life. So through simple calculation, one can realize that Demodex can reach astronomical numbers in a matter of 3 months (about 13 million mites).
Demodex is parasite which lives just under the surface of skin, such as in hair roots or the subcutis. At night, when we sleep, Demodex crawl out from a sebaceous gland or hair root and pollutes he skin surface with their excrement and their corpse. Furthermore, cosmetics and dirt which is left on our skin surface becomes stuck to their feet, before they return to the depths of our hair roots again. And Demodex is contagious and can be transfered from one person to another simply by rubbing cheeks together. This is the mechanism by which Demodex breeds.