Desert animals have adapted ways to either bear or avoid the heat and sun, as well as store, obtain or endure the loss of water in their harsh environment. Heat, sunlight and a lack of water are the major issues most organisms face in desert environments, although there are several deserts which are actually quite cold. Water is crucial to all life, however, and its lack defines deserts.
Food and water are both scarce in deserts. Plants are extremely dependent on available water for photosynthesis and cannot grow in its absence. Thus, the few plants that do grow are either extremely good at obtaining water, extremely good at keeping it, or both. Animals, unlike plants, have the ability to hide from the drying sun during the day, and burrowing is a very common habit in desert animals. Animals that do not burrow often rely on naturally occurring shade or other animals' burrows. Many desert animals are nocturnal, or are only active in the morning and evening, avoiding the hottest parts of the day.
The process of metabolism produces water while digesting fats and carbohydrates, and some desert animals, such as the kangaroo rat, are able to keep sufficient hydration through this method alone. Others, such as the gila monster or the camel, keep large stores of fat for use whenever food or water is scarce.