Animals that draw heat from the outside environment to keep warm are called
the answer: "temperature variable".
Animals that derive heat from the external environment to keep warm are called heterotrophs.
Heterothermic animals, also known as ectothermic animals, are those that rely on external sources of heat to regulate their body temperature and keep warm.
This is in contrast to endothermic animals, which generate their own heat internally through metabolic processes.
Examples of heterotherms include amphibians, reptiles, and some insects, such as bees and wasps.
These animals depend on the sun, hot surfaces, or even other animals as a source of heat.
As a result, these animals may hibernate during the colder months or migrate to warmer climates.
