They are closely related to spiders. Unlike spiders, their oval or elongated bodies are not divided into two distinct parts. Like spider the eight legs come from the front part of the body. The jaws of mites are reduced to clinging claws or piercing parts. The eyes are very small even for the size of the tiny mites.
Mites have two or four eyes depending on type or species.
Adult mites must breath air, but can stay underwater for a long time due to their tiny size. A tiny animal such as the mite has a small mass compared to its surface area and therefore needs little oxygen. Each mite has a dark hole on its body. The hole is the opening to long breathing tubes that go into the mite's body. These breathing tubes are called tracheae.