Which are the most poisonous snakes?

Every year about one milliom people are bitten by piosonous snakes, mostly in tropical regions of the world. Between 30,000 and 40,000 of these people die.

There are several groups of poisonous snakes, and their venom can attack the body in many different ways. venom can attack the blood, the nervous system or in the case of the rattlesnake, most of the body organs. The danger depends on how much venom is injected into the body through the snake's hollow fangs when it bites.

Rattlesnakes and copperheads are common hazards in North America, while vipers and their relatives, together with cobras and mambas, are common dangers in Africa and Asia. The spitting cobra is most unusual because it sprays venom into the eyes of its victim to blind it, rather than biting. Snake bites on humans sre nearly always acts of defence. This is because the snake thinks that it is being attacked.