A desert is a region that has very little or no rainfall. Many deserts are hot places, bare and rocky, or sometimes covered with sand or gravel. The Sahara Desert in northern Africa is a hot desert. In some hot deserts, temperatures can soar to over 50°C (120°F) during the day. There are no trees to give shade and few places to find water. Even so, some kinds of plant and animal are still able to survive. There are also cold deserts, such as the Gobi in Asia.

Areas of desert are found in the western USA and South America, as well as in Asia, Australia and Africa. The Sahara is the largest and hottest desert in the world. Most of it is covered by rock or gravel, only one tenth by sand. At night, with no cloud cover, the ground cools very quickly and temperatures drop to below freezing.

Many desert animals, such as the kangaroo rat or kit fox, keep out of the scorching daytime heat by hiding in cool burrows or under rocks. The animals emerge from their burrows as the sun sets. Cold-blooded reptiles, such as lizards, warm up their bodies in the morning sun before they go off to hunt. Even they shelter in burrows under rocks during the hottest part of the day.

Surviving without water

Desert animals have a number of ways to cope with the lack of water. The addax, an antelope from Africa, does not need to drink at all. The moisture in the plants it eats is all it needs.

Some types of darkling beetle live in Namib Desert in southern Africa. It is one of the driest areas of the world. The beetle stands on its head on foggy mornings to drink the condensation which trickles down its body.

Cacti

Cacti are common plants of the deserts of southwestern USA. They collect water from dew, fog or rain whenever it falls, and store it in their swollen stems. The saguaro cactus can grow up to 15 metres (50 feet) tall. Its stem makes a perfect home for the tiny elf owl, which uses hollows made by Gila woodpeckers to make its own nest. The cactus's spines help to protect the nest from enemies.