Sometimes animals are caught in such a situation that they can neither run away from their enemies nor fight with them. In such situations they become very tense. Different animals react differently to get rid of their tense moments.
To understand this mechanism of relieving tension let us take an example of a school boy who has done some wrong and is facing his teacher. He feels guilty and perhaps frightened also. He cannot run away or fight. He is caught in a tense situation, and somehow he must come out of it. So he does something looking incoherent like scratching his head or blowing his nose to fight off his tension. Such actions help him in relieving his tension.
For instances, when a mouse is cornered by a cat and cannot escape, it will sit up and scratch its face with its forelegs. A bird which is frightened of a cat will make pecking movements (when birds start striking with their beaks). A monkey relieves its tension by uttering different sounds. Similarly, dogs relieve their tension by barking. All these actions are meant for getting rid of tension. These are called displacement actions. Animals act in such ways to regain their normal state. Sometimes they can cause harm to others. All these actions are their reflex actions. These actions help animals to survive.
To demonstrate the reflex action a Russian scientist Ivan Pavlov carried out a famous experiment with some dogs. In this experiment, he showed some food to the dogs. Due to this their mouths got watered. At the same time he rang a bell. He repeated this for a few days and then began to ring the bell without showing the food. The dogs became so used to the association of the sound of the bell and the sight of the food that their mouths still watered even when food was not shown. This is called conditioned reflex action. This happens involuntarily when animals are trained for some purpose. They start doing these actions automatically. In a similar manner people learn studying and talking simultaneously.
