There are two types of worms that live on the face: Demodex folliculorum and Demodex brevis. The first one lives in our pores and hair follicles, and the second in fat glands in the lower layers of the skin. There are more pores and oil glands on my face than other parts of our body. Experts believe that there are hundreds of pieces of these grubs. But what they feed on is not yet known. Some claim that they feed on dead skin, while others feed on bacteria on the face. It is thought that they come back from the pores at night and come back again. Since Demodex does not have anus, it is believed that they kept the waste materials in their bodies until they died and they dissolved with their deaths. In this short review study, It will be discussed the determination of new waste evaluation technology by using these microorganisms.