A kangaroo rat can live its entire life, 2 to 5 years, without drinking water. Camels can only survive for a few months without water.
Camels need less water in the winter months than they do in the summer. They get some of the water they need from the plants they eat and, despite what many people believe, a camel's humps do not store water for the animal. A camel's humps are fat reserves that are converted to energy as necessary.
Kangaroo rats build their homes in humid underground shelters and coat their fur in an oily substance that helps them retain water. They have the ability to lower their own metabolic rate, which also conserves water.