How to Identify Spiders

Spiders are any arachnids of the order Araneae, of which there are about 40,000 species. They have two body segments, an abdomen and cephalothorax and eight legs. Spiders have no chewing mouth parts or wings and produce silk, but not all spiders spin webs. All but about 350 species are poisonous, but only about 200 pose a danger to humans. The following steps will show how to identify spiders.

Instructions

Difficulty: Moderate

1. Examine the arrangement of the eyes by looking at the "head" or cephalothorax. This is the most accurate way of categorizing the major group that a spider is in. The eyes can be been seen unaided in larger species but smaller ones may require magnification.
2. Check for two eyes on the left, two on the right and two in the center to identify the brown recluses and their relatives. These spiders rely on strong venom and frequently bite one time. They may release their prey and wait for it to die or leave their pedipalps (fangs) embedded in the prey and continue injecting more venom.
3. Identify hunters like wolf and jumping spiders as having an eye at the top left and right, two in the middle and four in a row at the bottom. These spiders capture prey by actively chasing it down rather than webbing or using powerful venom.
4. Expect other spiders to two have rows of four eyes each.
5. Note that other spiders capture prey by spinning a web. Insects get caught in the web and the spider may ingest it immediately or immobilize it by wrapping it in a cocoon of silk for later consumption.