Spiders are wingless and lack antennae. Most have six or eight eyes, bodies are highly variable in size and shape. Young and adults have eight legs and a pair of palpi by the mouth. Palpi are used much like antennae in insects and in males are used during mating. Mouthparts are a pair of chelicerae, each with a piercing tooth. Chelicerae are used to manipulate captured prey but all food intake is liquid.

Most spin webs of various sorts to capture prey or as a refuge. All spiders are predators. Most spiders are beneficial but a few (such as the widow spiders and the recluse spiders) are considered poisonous and should be avoided.  The stages are eggs, young (often called spiderlings) and adults. Size ranges from 1/8 inch to over four inches.

There are about 900 species of spiders in Texas and only a few are mentioned here.

Arthropods in this class are tarantula, recluse spider, southern black widow.