When it gets too hot in the desert, some desert birds shelter themselves in the holes of cacti.They not only keep cool but have water inside the cacti too. The hard outer coverings of some insects and scaly skins of reptiles are waterproof so that it stops moisture from leaking out of them. Animals that spend the day underground make a moist athmosphere in their burrows to cut down on water loss. Some do not even lose water form their bodies. Kangaroo rats have efficient kidneys that extract water from their food. The sand groust soaks up water when it finds some. A beetle climbs a sand dune and let water droplets to condense on its own body. The Australian native mouse has the same trick as the beetle. Cactuses are the best at storing water as they have shallow root systems to soak up liquids before they evaporate and spines, which loses less water to the air.