| Ectotherms | Endotherms |
| 1. Ectotherms do not have ability to generate heat in the body. | 1. Endotherms possess the ability to generate their own body heat. |
| 2. Ectotherms depend on the environmental sources to heat their bodies. E.g sunlight. | 2. Endotherms do not depend upon outside sources to generate heat. |
| 3. Most ectotherms are confined to warmer parts of the world. | 3. Endotherms inhabit coldest parts of the earth. |
| 4. Body temperature of ectotherms fluctuate according to ambient temperature. | 4. Body temperatures of endotherms remain constant and do not show fluctuations as per ambient temperatures. |
5. Metabolic rate of ectotherms is low.
E.g. Amphibians and reptiles. | 5. Metabolic rate of endotherms is high.
E.g. Mammals and birds |
