Mites

Most mites are tiny, less than 1 mm (0.04 in) in length, and have a simple, unsegmented body plan. Their small size makes them easily overlooked; some species live in water, many live in soil as decomposers, others live on plants, sometimes creating galls, while others again are predators or parasites. This last group includes the commercially important Varroa parasite of honey bees, as well as the scabies mite of humans. Most species are harmless to humans but a few are associated with allergies or may transmit diseases.

Many mites are parasitic on plants and animals. One family of mites, Pyroglyphidae, or nest mites, live primarily in the nests of birds and animals. These mites are largely parasitic and consume blood, skin and keratin. Dust mites, which feed mostly on dead skin and hair shed from humans instead of consuming them from the organism directly, evolved from these parasitic. Plant pests include the so-called spider mites (family Tetranychidae), thread-footed mites (family Tarsonemidae), and the gall mites (family Eriophyidae).[24] Among the species that attack animals are members of the sarcoptic mange mites (family Sarcoptidae), which burrow under the skin. Demodex mites (family Demodicidae) are parasites that live in or near the hair follicles of mammals, including humans.