Spiders have been on this planet for 400
million years. They are predatory insects
that eat other insects (even other spiders)
and small animals. Most spiders are
harmless to humans. The most deadly
spiders are the black widow spider, the
yellow spider, the hobo spider and the red
legged spider. These spiders have enough poison, or venom, to kill with one
bite. Spiders are able to control how much venom they inject into their prey. In
fact, they can even bite without injecting any venom. This is called a dry bite.