The smallest species of spider in the world is the patu digua. The male patu digua is only as large as the head of a pin.
Not much is known about the patu digua. It is too small to photograph, and according to the Guinness Book of World Records, even photographing this species with a microscope will not present a clear picture. What is known is that this spider lives in Western Samoa in the moss that grows there.
By contrast, the largest known spider species is the goliath bird-eater tarantula. This spider, as its name suggests, is large enough to eat a bird and has a leg span of around 11 inches. It is found in Venezuela, Brazil, Guyana and French Guiana.
One of the smallest and most venomous spiders in the world is the black widow spider. The venom in a black widow spider is 15 times more deadly than a rattlesnake, but luckily, the spider will only bite in self-defense.
One of the largest dangerous spiders in the world is the Northern funnel web spider. It lives in Australia and can grow to be more than 3 inches long. It lives in trees, is attracted to water and can sometimes be found in swimming pools. The venom from this spider is one of the most deadly known to man and can kill a full grown adult in less than 15 minutes.