Why do spiders have eight legs?

Spiders have eight legs because they are arachnids, a class of joint-legged invertebrate animals. The number of legs in spiders is determined by their evolutionary history and adaptation to their environment. Having eight legs allows spiders to walk, crawl, climb, and catch prey efficiently. Additionally, having multiple legs helps spiders maintain their balance and stability while navigating their surroundings. Overall, the eight-legged body plan of spiders has proven to be successful in helping them survive and thrive in various habitats.