These creatures feed on marine worms and are identified by their oval shell and spinelike tail. Their bodies consist of the cephalothorax and the abdomen. The cephalothorax supports the eyes, mouthparts, and legs while the abdomen bears the genital structures, spiracles, anus, and spinnerets. Most spiders have eight or fewer eyes and all of them are simple. The number and placement of eyes can be used in identification.
Spiders have poisonous glands which open from the chelicerae.
Although all spiders have venomous glands, they are rarely harmful to humans. In fact, only a few species in the United States are considered dangerous. Spiders also have pedipalps which are located behind the chelicerae and are clubbed in male spiders. Spiders have seven-segmented legs and most have two or three claws. Characteristic bristles and hair on the legs is often used inidentification.