Jumping spiders are easily distinguished from other spiders by their four big eyes on the face and four smaller eyes on top of the head. Found worldwide, there are more than 5000 known species.  Although a jumping spider can jump more than fifty times its body length, none of its legs has enlarged muscles. The power for jumping comes from a quick contraction of muscles in the front part of the body increasing the blood pressure, which causes the legs to extend rapidly, much as the hydraulics in a low-rider car.

Salticids are perhaps as old and diverse as mammals, though not many humans know of their world. Many salticids are colorful, they take on a variety of body forms. Phidippus audax is one of the most common jumping spiders in North America. It is commonly called the "bold" or "daring jumping spider."  

1. Bugguide.net, Jumping Spider - Phidippus otiosus
2. Arthur V. Evans, National Wildlife Federation Field Guide to Insects and Spiders of North America (Sterling, 2007).