Mites (Latin Acari) - a subclass of arthropods from the class of arachnids (Arachnida). The most numerous group in the class: more than 54 thousand species have been described, including 144 fossils. Such a heyday of ticks was achieved due to the fact that in their historical development they acquired microscopically small sizes, which enabled them to master the upper layers of the soil, rich in decaying plant remains.
The zoology section that studies ticks is called acarology.
The length of the mites is usually 0.2-0.4 mm, but can reach 5 mm. The body is whole or divided into two parts, which do not correspond to the cephalothorax and abdomen of the spiders, - the border passes somewhat closer to the anterior part of the body. Usually there are 6 pairs of appendages, of which 4 rear pairs in most adults are legs (larvae, usually six-legged).