The Miridae are unique within the Heteroptera in their possession of specialized setae known as trichobothria on the middle and hind femora. Most species lack the pair of ocelli found situated between the compound eyes of the majority of heteropteran species; the exception to this rule is the subfamily Isometopinae, which is thought to be the sister group of all remaining Miridae (the most basal lineage). The hemelytra, or forewings, nearly always have a well-demarcated cuneus, a triangular structure that is found in some other groups such as the non-parasitic Cimicoidea (bed bugs and their relatives) and whose anterior margin if formed by the costal fracture.

The pretarsus (claws and associated structures) shows much greater variation in the Miridae than in most other hemipterans, and provides many features crucial for understanding the subfamily classification of the group. As in most other bugs, the claws in the Miridae are symmetrical, the right and left claws being similarly developed. They may bear a pulvillus, a fleshy pad, on the ventral or interior surface of the claw; the exterior claw surface is sometimes ornamented with a few claw hairs of variable length. Between the claws are found the parempodia, paired, structures that arise from the distal end of the unquitractor plate. The parempodia are frequently in the form of common setae and are symmetrically developed. They may also be weakly to rather strongly fleshy and either divergent or convergent apically. Also present in some Miridae are structures known as pseudopulvilli that arise from the base of the claws. In some groups the pseudopulvilli have the appearance of parempodia whereas in others they look more like pulvilli. [4]