Most species of spiders that occur in the U.S. are harmless to humans. They destroy many pestiferous insects and are therefore beneficial.
Spiders are arthropod relatives of insects.
Spiders have a body of two distinct sections. The cephalothorax is the anterior and smaller part. It bears the eye, mouthparts and legs of the spider. The abdomen is the second part. It includes most of the internal organs, the reproductive organs and silk glands.