North America is home to about 3,400 of the categorized 40,000 species of spiders in the world. Spiders are known as Arachnids and fall under the class Chelicerata and order Araneae, taking various shapes and forms as well as colors and behaviors. Regardless of the individual species, all spiders consist of eight legs and feature two-piece bodies made up of the cephalothorax (front) and abdomen (the bulbous rear). The cephalothorax contains a multiple-eye arrangement (the number varying by species), mouth parts and the legs while the abdomen holds the the silk-producing facilities of the spider.
Spiders can generally be identified by the type of web they create though not all webs are used to capture prey. Some are used in courtship rituals while others are used to secure egg sacs. Silk is produced by specialized glands found in the abdomen of the spider that are formed of liquid protein generated within the body. This protein hardens once it is outside of the body and released through the rear of the abdomen, guided by spinnerets that allow the spider to customize its release as needed. It is not wholly uncommon for spiders of different species to share a web or a spider to steal another's prey. Other species rely on the element of surprise and bury themselves in loose soil, springing out when prey passes - injecting them with powerful subduing venom.
There are a total of 77 North American Spiders in the Insect Identification database. Entries are listed below in alphabetical order.