What Do Animal Tails Do? A Full Guide to Balance, Defense and Communication

An animal's tail is a structure extending from the end of the body of many animals, made up of vertebrae, muscles, and hair or scaly skin, and its form varies greatly from species to species. Although a few animals such as humans and apes have no tail, for the vast majority of mammals, reptiles, fish and birds, the tail is an indispensable organ in daily life.

Maintaining balance is one of the most common functions of the tail. Cats adjust their center of gravity with their tails when jumping and running, kangaroos use their thick tails as a support when standing, and many primates can also hook their tails around branches to help them move. For aquatic animals such as fish and whales and dolphins, the tail is the main propulsion organ, and swinging it left and right or up and down generates forward thrust.

The tail also takes on the important task of transmitting information. A dog wagging its tail usually means it is happy or excited, some deer raise their white rump patches to warn companions that danger is near, and beavers slap the water to alert their colony. Some species have strikingly colored tails that can divert a predator's attack target when fleeing, buying a chance to escape.

In addition, the tail has uses such as keeping warm and defense. Animals in cold regions curl up their fluffy tails to cover their mouths and noses against wind and snow, and certain lizards can drop their tails to survive when in danger, then gradually regenerate them. The tails of some rodents and monkeys can also store fat or grasp food, showing that this seemingly inconspicuous part plays many roles in animal survival.