Only Few Snakes Are Poisonous Among A number Of Their Kinds - Snakes are long, thin reptiles. They do not have legs and they slither along the ground. Snakes belong to the order of animals called reptiles. There are about 2,400 species of snakes in the world. Snakes kill one hundred people every year. According zoologists most of the snakes are not harmful for the human. Only few are poisonous snakes among a number of kinds.