Animals store glucose in the body in the form of glycogen. The need to store energy is to have some amount of energy in the body to be used at the time of starvation.
Excess of the glucose in the body is stored in the form of glycogen.It is a polysaccharide of glucose which is structurally very compact.
This property allows it to get stored and used later as a source of energy when the body is in starvation condition.
