The largest species of tarantula is also called the goliath bird-eating spider, and its leg span can reach up to 12 inches. They are burrowers and spend the majority of their lives inside their homes, never moving more than a few feet away even while hunting. They prefer swampy areas near water, where their brown bodies will blend into the surroundings. Considered extremely aggressive, these spiders do not make good pets, and are prone to biting -- their 1-inch fangs can do a great deal of damage, although the venom is not fatal to humans. The typical diet of this spider includes amphibians, rodents, insects, snakes and the occasional small bird.