Cobras are a kind of venomous snake found in Africa, India, the Middle East and Indonesia. They rear up and flatten out their neck like the snake in the picture when they are scared.
Cobras are the snake of choice for snake charmers, who seem to hypnotise a snake by playing a musical instrument in front of it.
Rattlesnakes cause most snake bite injuries and deaths in America. They are a threatened species now because people kill so many of them.
Rattlesnakes scare off predators by rattling their tails. The rattling sound is made by special scales at the end of the rattlesnake's tail.
Snakes are a type of reptile that has no legs. They come in many colours and patterns, and some kinds of snake can grow to be several metres long.
Snakes jaws do not lock open like ours do, but can open a huge way. They can swallow small animals that are much bigger than their heads. Snakes only need to eat every few days. Some snakes are very poisonous and can kill a person in one bite. Other snakes kill their prey by wrapping themselves around it and suffocating it. You should always be careful around snakes.
Some kinds of non-poisonous snake are sold as pets, but often a special license is needed and pet snakes should still be treated with care as they might eat other household pets and have been known to kill very small children.