Give scientific reason
Body temperature of reptiles in not constant.
Reptiles are cold blooded organisms or poikilotherms which means they are not able to regulate their body temperatures. Their body temperatures change with the change in the temperature of the environment. For example, if the outer temperature rises their body temperature also rises and vice or versa. This can be explained from the observation that when the temperatures drops, these reptiles bask themselves in the sun whereas when the temperatures are high, they would hide under the shades.