You may have noticed that sometimes when you try to kill a lizard, you only manage to cut off its tail. When an enemy attacks a wall lizard it often flees, leaving behind some portion of its tail. The detached tail keeps wagging for some time. This confuses the enemy and the wall lizard escapes. That is how it protects itself from its enemies. The wall lizard can easily detach a portion of its tail at its will. The bones in its tail are joined together loosely, so that any portion of the tail can be separated easily from the main body. When the tail is separated, it does not lose much blood because the ends of the blood vessels are almost sealed. It is, therefore, possible for the wall lizard to get rid of its tail. The lizard soon grows a new tail. Scientists have studied more than 3,000 species of lizards till date. It has been found that their bodies are usually divided into three distinct parts — head, trunk and tail. Most species have four legs. Although most lizards are hatched from eggs, a few are born directly. Most lizards feed on insects. A few of the larger species are more than 3 metres long. They are quite frightening in sight. They can easily kill a fairly large animal with one blow of their long, strong tails. These lizards are mostly found in tropical countries. A number of African species live in tropical forests where they climb trees. Some of them have flattened flaps of skin, which can be stretched down between hind and forelimbs to jump from tree to tree. Lizards can run fast, and some can swim or even glide through the air. Like lizards, crabs and lobsters are also able to get rid of their legs in a way similar to the lizard detaching its tail. When a fish catches the leg of a lobster, it jerks away its leg and escapes. These are the defence mechanisms that enable these animals to survive.