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What Makes a Mammal? Blood

What's the advantage of being warm-blooded?

Unlike fish, reptiles and other cold-blooded animals, mammals can maintain their body temperature over a wide range of conditions. This enables us to live in a great variety of habitats - fromthe frigid arctic to the scorching Sahara.

Compare what happens to the body temperatures of the desert lizard and the fennec fox as the sun rises and sets.

Desert Lizard:
The lizard's body temperature rises and falls with that of the outside air. After a cold night, it must bask in the sun until its body is warm enough to function.

Fennec Fox:
The fox maintains it's body temperature within a few degrees even when air temperature changes. So it can be active both during the day and night.

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