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. At the end of the abdomen are six fingerlike structures called spinnerets. This is where the silk of the spider is spun. This silk is used to spin webs and create sacs where the eggs are laid. The females tend to be much larger than the males and in some cases eat the males after mating.