Jumping Spiders

I often encounter jumping spiders on our back deck and enjoy watching them.  Identified by their small size, fuzzy appearance and prominent frontal eyes (they have 3 smaller pair as well), these "cute" arachnids stalk a variety of insects, some much larger than themselves.

Unlike many of their cousins, jumping spiders do not construct webs to snare prey; however, they may venture onto the webs of other spiders to snatch insects caught in the silk.  More often, these small predators hunt from a perch; from there they pounce on their prey or stalk victims before striking.  Venom is used to immobilize larger prey but generally causes only mild, local irritation in humans.  A hydraulic-like vascular system allows these spiders to jump up to 50 times their body length; when doing so, they usually release a "life-line" of silk to permit a quick retreat should they miss their quarry.  Silk is also used by females to encapsulate their eggs (which are attached to vegetation, rocks or human structures) and by both sexes to mark their den site.

More than 5000 species of jumping spider are found across the globe; while most live in tropical regions, about 300 species inhabit North America and some species are found high in mountainous ecosystems.  Though most species are diurnal carnivores, some feed on nectar as well.