Just saying the word "spider" can elicit responses of fear or awe from people, but regardless of which side you fall on, there's a good chance that there is quite a bit you don't know about eight-legged arachnids. That's because, simply put, spiders are amazing creatures. There are 40,000 different species of spiders living on every continent except Antarctica, and nearly every one of those species is poisonous. Spiders can range in size from tiny to nearly the size of a small puppy. Here are some other amazing facts about these curious creatures.