Spiders belong to the class Arachnida, which contains organisms with four pairs of legs, no antennae and two body regions. A shield-like carapace covers the head and the area from which the legs arise. Their mouthparts, or chelicerae, function vertically.
The jumping spiders belong to the family Salticidae and are sometimes called salticids. All species are small, usually less than 15 mm long. They are easily identified by their eye arrangement, which is in three rows. Jumping spiders do not construct webs, but actively hunt prey during the day, pouncing on their luckless victims. Many are brightly colored, sometimes with iridescent chelicerae as in the genus Phidippus. Some species such as Plexippus are commonly found on or around buildings.