Spiders are not insects but they are related as spiders and insects are both arthropods (animal having an exoskeleton and jointed legs). Spiders are however closely related to mites, ticks, and scorpions which are known as arachnids. Unlike insects, spiders have eight legs rather than six. They have no antennae and their bodies are divided into two segments. Spiders have silk-spinning structures called spinnerets at the back end of their abdomen. Most spiders have eight eyes of various shapes and sizes, however, the brown recluse has six eyes.

Spiders are predators that feed on primarily on mites, earthworms, living insects and other small arthropods. They are considered to be beneficial because of the large number of insects and difference pest species they prey on. All spiders have venom which is excreted through their hollow fangs and used to immobilize their prey in order to begin the digestion process. Spiders feed by liquefying their prey with digestive fluids that are either injected into or regurgitated onto their prey then they suck in the digested food.

Most spiders are active at night and will dart away when disturbed unless they are tending to egg sacs or young. During the day, they usually inactive remain hidden in cracks and crevices, in their webbing, under rocks, etc.

There are about 3,000 species of spiders in the United States. Spiders rarely bite people and most species are found to be harmless. Many spiders cannot penetrate human skin with their fangs and the bite of those spiders that can, usually results in no more than a slight swelling or inflammation. However, some people may experience allergic reactions to spider bites and a few species of spiders are known to produce bites that may pose serious health risks to people. These spider species include the black widow and the brown recluse as well as their relatives. The black widow spider possess a neurotoxin, whereas, the brown recluse possess a cytotoxin which may produce an ulcerating sore or lesion at the site of the bite.