They're the big, hairy spiders of our nightmares. And it's no wonder we are afraid. Tarantulas are the biggest of all the arachnids. These spiders are killing machines perfectly adapted to their habitats. And the biggest and battiest of them all is the Goliath. It can grow to nearly a foot across with fangs an inch long. The Goliath makes itshome in the remote rainforests of South America.

Night is when the Goliath is most active. But for these ambush predators, hunting means lying in wait. Near the entrance to her burrow, she lays down a silk welcome mat. It acts like a tripwire letting her know when something has ventured within range. Even with eight eyes, Goliaths like most spiders have weak vision. They are alerted to the presence of prey by vibrations rippling across their sensitive hairs. It's only a matter of time before some hapless creature like this floor mouse wanders too close and brushes against the silk. It's like ringing a dinner bell. The Goliath's venom proves fatal to this mouse.

But for most people, the tarantula's bite is no worse than a bee sting. According to researchers, there has never been a single confirmed human death from a tarantula bite. Perhaps knowing the facts about these ancient predators can help turn human fear into fascination.