Today's focus is on Carl, a Nile crocodile who lives with his 30 brothers and sisters in Zambia's Luangwa River. It is nearly a week since Carl hatched from an egg, and he is 24cm long from his snout to the tip of his tail. For the first five weeks, his mother will provide him with loving care and protect him from predators, including other adult crocs. However, he will grow up to six metres long and could live for over 50 years. Reptiles emerge into the world with most of the skills they need to survive, and Carl could walk and swim right away. He is cold-blooded and unable to produce heat within his body, but already he knows how to warm himself up with the sun's rays. When he's grown up, Carl will hunt much bigger animals like antelope and buffalo, but his main food will be fish.