Goliath Birdeater Spider

• Venom
Like all tarantulas, they have fangs large enough to break the skin of a human (1.9–3.8 cm or 0.75–1.5 in). They carry venom in their fangs and have been known to bite when threatened, but the venom is relatively harmless and its effects are comparable to those of a wasp's sting. Also, when threatened, they rub their abdomen with their hind legs and release hairs that are a severe irritant to the skin and mucous membranes. They have urticating hairs that can even be harmful to humans, and are considered by some to be the most harmful tarantula urticating hair of all. Tarantulas generally bite humans only in self-defense, and these bites do not always result in envenomation (known as a "dry bite"). The Goliath birdeater has poor eyesight and mainly relies on vibrations in the ground, which it can sense from within its burrow.