; order Araneae, suborder Araneomorphae)
Family of spiders which have only two tarsal claws. They are medium to small spiders in which the carapace is square-fronted. The anterior median eyes are much larger than the others and members of this family have the greatest visual acuity of any arthropod, also perhaps being sensitive to the colour and plane of polarized light. Prey is jumped on from a distance of a few centimetres by rapid elevation of the internal body pressure which extends the legs. Many species mimic ants, and all have complex visual courtship and threat displays. Most of the 4000 or so species are tropical, although there are northern temperate and even arctic species.
Subjects: Zoology and Animal Sciences.