At cool times of year, reptiles are active only at midday, when it is fairly warm. When it is hot, they retreat to the shade and emerge only in the cool of the evening. Scaly skin Reptiles may sometimes look slimy, but their scaly skin is perfectly dry. Indeed, it keeps a reptile's body moisture in so well that it can survive in deserts better than most animals. One of the remarkable things about this scaly skin is that it can change colour.
Many reptiles turn a darker colour when basking in order to absorb the sun's warmth better.
Chameleons can change colour to match their background and avoid being spotted by predators. Unlike mammals, reptiles grow all through their lives, but their skin does not. Every now and then, they must shed or slough their skin to reveal a soft new one underneath. Snakes slough off all the old skin in a single piece. Although most live in the warm tropics and subtropics, lizards inhabit a wide range of different environments.