Many animals and humans bask in the sun to warm up from time to time. But for cold-blooded animals, like reptiles, this is the only way they can increase their body temperature.
To soak up the sun’s warmth, the animal will lie in full sun in such a way that his entire body gets full exposure. When his body has warmed up enough, he will move to the shade, or to water, in the case of crocodiles.
By lying in the sun, these animals also jumpstart their metabolism and get a good dose of vitamin D. Their scales protect them from harmful UV rays and getting sunburnt.
