Spiders are called arachnids.

They differ from insects because they have two body parts and eight legs. Insects have three body parts and six legs. There are different ways to categorize spiders. If you start with spider eating habits, they are carnivores, and then a simple two category typology follows. Spiders are either webbies or hunters. Some species use webs to catch their prey. Other species actively hunt their prey on air, land or water without the assistance of a web.

Spiders range in size with jumping spiders among the smallest spiders that people commonly see in their daily lives. The goliath bird eater tarantula of South American, on the other hand, ranks as the largest spider in the world. Because spiders are carnivores (meat-eaters), people fear them. Not only do spiders bite humans, but the bites of a few spider species cause a great deal of pain, and in rarer instances, death. By far, the vast majority of spider species are not dangerous to humans. Rather, most common spiders are considered beneficial. They eat insects that humans consider pests.