Theory:

1. DESERTS are the driest places on earth and sometimes go for months, or even years, without rain. But even the desert animals cannot survive without water, or for long periods in the scorching sun, so they have had to find different ways of coping with the harsh conditions. For example, gerbils spend the hottest part of the day in cool underground burrows. And strange insects called darkling beetles are experts at catching drops of moisture on their legs, then lifting them into the air until the drops trickle down into their mouths. Not all deserts are endless seas of rolling sand dunes. Some are rocky or pebbly and dotted with small bushes while others are sprinkled with colourful flowers during the spring.
 
2. There are more than 2300 different kinds of snakes around the world, ranging from just fifteen centimetres long to more than eleven metres. Most snakes are quite harmless — but there are a few that are so poisonous they can kill a human being with just one bite. Most snakes lay eggs, but there are many which give birth to their young. In the dry, rocky deserts of America lives a rather evil-looking snake with a very bad reputation. Its frightening rattle can be heard as far as thirty metres away, and it can strike with lightning speed.
 
3. But the rattlesnake, or ‘rattler’ as it is sometimes called, prefers to avoid people if it possibly can. It holds its tail upright and rattles the end whenever it is disturbed, in the hope that the intruder will go away. However, if its warnings are ignored—and it feels threatened—it will coil ready to bite. But the rattler itself cannot hear the noise its own tail makes. Like most snakes, it ‘hears’ things through vibrations in the ground. If a person walks nearby the snake can feel the movement. But if the same person were to shout, it would not hear a thing. Rattlesnakes are very common and widespread animals, living right across the American continent from Canada to Argentina. They feed on a variety of prey, including mice, voles, rats, chipmunks and many other small animals. Rattlesnakes kill their prey with venom. Like all snakes, they swallow the unfortunate animals whole. Few snakes have to eat more than once a week and some, such as the larger pythons, can survive for a year or more without eating.
 
4. Mongooses like to hunt together, but they always keep a lookout for dangerous predators nearby. Poking their noses into holes, overturning rocks with their paws and scratching the ground with their sharp claws, banded mongooses are very amusing animals to watch. A common sight in many parts of Africa, they travel in groups of about twenty to forage for beetles, millipedes and other small creatures.
 
5. They like to hunt together, keeping in touch whenever they go out of sight behind rocks or bushes by twittering and calling. Always on the lookout for danger — hawks, eagles and large snakes — they warn one another with a special alarm call if they spot anything suspicious.
 
6. Mongooses are famous for being able to kill snakes without getting hurt themselves. Their reactions are so fast that they can dodge each time the snake strikes. They continually make a nuisance of themselves until, after a while, when the snake gets tired, they quickly dive in for the kill.
 
7. All the female mongooses have their kitten at about the same time. They are raised by the whole group in a den made inside an old termite mount or hollow log. When most of the adults are out looking for food, one or two males stay behind to stand guard until the others return for the night.
 
8. Another animal which lives in the desert is the camel. Camels were first domesticated by people many thousands of years ago. In the wild, camels usually live in small groups of up to thirty animals. Camels have long, shaggy winter coats to keep warm and shorter, tidier coats in the summer to keep cool. A thirsty camel can drink as such as thirty gallons of water — that’s about five hundred full glasses — in just ten minutes. Normally, however, it gets all the moisture it needs from desert plants and can survive for up to ten months without drinking any water at all.
 
9. There are two different kinds of camel. One, known as the Dromedary, has only a single hump; the other is called a Bactrian camel and has two humps. The humps help the animal to survive in the desert, by acting as storage containers. But they don’t store water — as many people wrongly believe — they are full of fat. This fat nourishes the camels when food is scarce. If they have nothing to eat for several days, their humps shrink as the fat is used up. There are many other ways in which camels are adapted to desert life. Their mouths are so tough that even the sharp thorn cannot pierce through.
Reference:
National Council of Educational Research and Training (2006). Honeysuckle. Desert Animals (pp. 112-120). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.