Mite

Mites are small arachnids historically grouped in the subclass Acari, spanning two large orders, Acariformes and Parasitiformes, though recent genetic analysis does not recover the two as each other's closest relative within Arachnida. Most mites are less than one millimeter long, with a simple, unsegmented body plan that makes them easy to overlook; some live in water, many live in soil as decomposers, others live on plants and sometimes create galls, and still others are predators or parasites, a group that includes the commercially destructive Varroa parasite of honey bees and the scabies mites of humans. Most species are harmless to people, but a few are associated with allergies or may transmit disease.