There are about 37,000 species of spiders in the world, and only a few are dangerous to humas.

One of the most famous is the female black widow . The male also has a poisonous bite, but its too small to be dangerous.

Female black widows are dangerous for two reasons: Their poison is powerful, and they often live near people. Every year in the United States, about 3000 poeple are bitten by black widows. The spiders' bites are very painful, but deaths are rare.

Black widows can be found in every state except Alaska, but most are found in warm parts of the country. They like to hide in old buildings, stacks of wood, and other dark, moist places.

Widows don't go cahsing after people, of course. But they will bite to protect themselves or their eggs. So always be careful where you put your bare hands!