Ectotherms:

(i) These are cold blooded poikilo-thermal animals.

(ii) Their body temperature changes with the change in surrounding temperature.

(iii) E.g., Many plants, aquatic animals and small animals, like humming birds.

Endotherms:

(i) These are warm blooded homoiothermal animals.

(ii) They maintain constant body temperature despite of changes in ambient temperature.

(iii) Eg: Most mammals.