A tarantula is a large, hairy spider that looks frightening but is usually harmless to humans. Some of the biggest species can be nearly as wide as a dinner plate when their legs are spread out, and they're covered in fuzzy hair that makes them look even more intimidating. Despite their scary appearance, most tarantulas are quite docile. Many species have bites that are similar in pain to a bee sting, and they'd much rather run away than attack.

Tarantulas live in warm climates around the world, from the deserts of the American Southwest to the rainforests of South America. They hunt at night, pouncing on insects, small lizards, or even mice. Unlike web-spinning spiders that wait for prey to get tangled, tarantulas are active hunters that chase down their meals.

Some people keep tarantulas as pets because they're fascinating to watch and relatively easy to care for. These spiders can live for decades: females sometimes reach 30 years old. When threatened, a tarantula might flick tiny barbed hairs from its abdomen that can irritate a predator's skin, giving the spider time to escape.

Scientists have identified more than 900 species of tarantulas, each adapted to its particular environment.