Scorpions are eight legged venomous arachnids. They have a long body with an extended tail with a sting. The average adult scorpion is about 3 inches in length. The longest scorpion is the African scorpion, which can be 69 inches long. There are about 1,750 species of scorpions worldwide.
The evolutionary history of scorpions goes back to the Silurian, 430 million years ago. They have adapted to a wide range of environments, and live on all continents except Antarctica. There are 13 living families. Only about 25 species have venom which can kill a human being.