Why do crocodiles sit with their mouths open ?
Crocodiles, like all reptiles, have a skin covered in scales. This skin is designed to hold IN moisture, and to lessen heat loss. They are ectothermic (cold blooded) and therefore derive their body temperature from the surrounding air. As a result, they bring their temperature up by basking in the sun or absorbing it from warmed surfaces like rocks. They do not have sweat glands. If a Crocodile gets too warm, it can only reduce it's temperature in three ways: get in the shade; get in the water; or sit quietly with its mouth wide open. The body heat therefore is lost through the soft, moist skin of the mouth and tongue. They bask in the sun to heat up, and if they ever overheat they sit with their mouths open to cool down.