A camel's hump is fat
A CAMEL does not store water in its hump; it stores fat, which it can break down for energy when food is scarce, and the hump shrinks and flops over as it is used. Keeping the fat in one place rather than spread under the skin also helps the rest of the body lose heat. Camels save water in other ways: they barely sweat until their body temperature climbs, and their droppings are dry.
When a camel does find water it can drink more than a hundred litres in a matter of minutes. Long eyelashes, nostrils that close and thick pads on the knees and feet make it well suited to sand. A camel with one hump is a dromedary, and one with two is a Bactrian camel.
Big ears and sideways snakes
The FENNEC FOX of the Sahara has the largest ears relative to its body of any fox. They let heat escape from its blood, and they are sensitive enough to hear insects and rodents moving under the sand. Its paws are furry underneath, which protects them from hot sand and helps it grip. It can go a long time without drinking at all, getting most of its water from its food.
The SIDEWINDER, a rattlesnake of the deserts of the south-western United States, moves in a sideways looping motion, so only a small part of its body touches the hot, shifting sand at any moment and it can travel up sandy slopes where other snakes slide back. The ROADRUNNER can run at around thirty kilometres an hour and is quick enough to catch and eat small rattlesnakes.
Scorpions glow, and a lizard led to a medicine
Shine an ultraviolet torch on a SCORPION at night and it glows blue-green. The glow comes from substances in the hard outer layer of its body, and scientists are still debating what it is for. It makes scorpions easy to find in the desert dark, which is how researchers count them.
The GILA monster of the south-western United States and Mexico is one of the few venomous lizards. In the 1990s scientists studying its saliva found a substance that helps control blood sugar, and it was developed into a medicine for type 2 diabetes. That discovery helped lead to a whole family of drugs now widely used.
Living without drinking
Some desert animals hardly ever drink. The ADDAX, a pale antelope of the Sahara that is now critically endangered, gets almost all its water from the plants it eats, and the ORYX can let its body temperature rise during the day rather than wasting water by sweating. The JERBOA, a tiny hopping rodent, and many desert lizards get what they need from food and from the dew.
Many desert creatures avoid the heat by coming out only at night. The rest of the grid holds the MEERKAT, the JACKRABBIT, whose big ears also shed heat, the GECKO, IGUANA and LIZARD, the COBRA, the TORTOISE, the VULTURE, the COYOTE, the ARMADILLO, the CARACAL, the HYENA and the GAZELLE. Our deserts page covers the places themselves.