Like the Chilean rose tarantula and other hairy New World members of the Theraphosidae family, the Goliath birdeater tarantula also employs "flying attack hair" when threatened. But as one of the biggest spiders in existence, the Goaliath birdeater also boasts a remarkable set of fangs. Measuring up to 1.5 inches long, it uses these fangs as a means of defense, often making a hissing noise by rubbing together its back legs before doing so. Mercifully for humans, the venom released by this super-aggressive critter is relatively mild. Residing within the swamps and marshes of South American rainforests, the Goalith birdeater’s diet does not normally consist of warm-blooded feathered vertebrates as its name would suggest; these massive arachnids prefer to munch on insects and the occasional rodent, snake or lizard (although early 20th century explorers reputedly witnessed one munching on a scrumptious hummingbird).