Spiders (order Araneae) are the largest order of the class Arachnida, distantly related to other groups of arthropods, such as insects, which should not be confused. The order Araneae is seventh in total species diversity compared to other diversity of organisms. The group is abundantly represented on every continent, except Antarctica. All are predators, usually solitary, small animal. They have poison glands on the chelicerae, with which paralyze their prey. Produce silk (see spider silk), call or web spider, which they use to weave networks of hunting, shelters and even be upholstered with the wind. To date over 42,000 described species of spiders in January, and 110 families have been collected by taxonomists, even so, there is still confusion within the scientific community, as evidenced by the approximately 20 classifications have been proposed since 1900.2 Only a few groups are actually dangerous to humans. The specialty that deals with the spiders and other arachnids called arachnology. Some people suffer from arachnophobia, fear of spiders.