Miridae are small, terrestrial insects, usually oval-shaped or elongate and measuring less than 12 millimetres (0.5 in) in length. Many of them have a hunched look, because of the shape of the prothorax, which carries the head bent down. Some are brightly coloured and attractively patterned, others drab or dark, most being inconspicuous. Some genera are ant mimics at certain stages of life. The Miridae do not have any ocelli. Their rostrum has four segments. One useful feature in identifying members of the family is the presence of a cuneus; it is the triangular tip of the corium, the firm, horny part of the forewing, the hemelytron. The cuneus is visible in nearly all Miridae, and only in a few other Hemiptera, notably the family Anthocoridae, which are not much like the Miridae in other ways. The tarsi almost always have three segments.