The body design of insects is very suitable for desert life. That is why there are so many insects in the desert. The hard outer covering of an insect (the cuticle) is made of a tough waterproof substance (chitin). The moisture is trapped inside the body and they loose less moisture by evaporation than other animals. When an insect breathes, it does not exhale continuously like you do. It waits until there is too much carbon dioxide in its body before it exhales once. Water loss while breathing is kept to a minimum. Most desert insects do not drink at all. They get enough moisture from their food to survive. They do not have to spend time finding waterholes. That is why they can live in the dry deserts. A lot of insect eggs are hidden underground. They wait for the rains to hatch and come out. At that time, there are lots of ephemeral plants and they have plenty of food. When they come out to the surface, they grow and lay eggs quickly, before they die. These eggs will wait for the next rains. In that way, some desert insects are able to escape from the harsh desert life and come out only when there is rain and food.