Fats are lipids constructed from glycerol and fatty acids, whose major function is energy storage. Because of the motile nature of animals, they must carry their energy stores with them; as a result, a very compact reservoir of fuel is needed, i.e. fat. For example, humans store their food reserves in subcutaneous layers of adipose cells, surrounding muscles and other internal organs. Displayed above, however, is a quite unique adaptation of an animal in response to energy storage. Contrary to popular belief, a camel’s hump does not hold water. In actuality, a camel’s hump is a giant mound of fat, weighing up to 80 pounds! The only animals with a hump, camels can survive up to two weeks without food, thanks to this energy-storing feature. This is extremely advantageous in desert habitat, where food can be scarce for long periods of time.