Crocodiles are a distinctive group of reptiles with a specific way of life. There are 22 species of crocodiles in the world, which constitute a separate order. Crocodiles are very different from other reptiles by their body structure and are the closest relatives of dinosaurs. In view of this, they are even separated into the subclass Archosauria (i.e. ruling reptiles) within the class Reptilia.
The length of different species varies from 1.5 m (dwarf crocodiles) to 10 m (Nile crocodiles). All crocodiles have an elongated, slightly flattened body, a short neck and a large head with a strongly elongated face. Crocodiles have short legs on the sides of their body, like all reptiles, and not under their body, like birds and mammals. This leg arrangement affects the way crocodiles move.
All crocodiles have a long, thick tail. The tail is flattened at the sides and acts as a steering wheel, engine and heat controller. It is characteristic that crocodiles have eyes and nostrils at the top of the skull. This allows them to breathe and see while their body is fully immersed in water. Also, crocodiles can hold their breath and stay under water without surfacing for up to 2 hours. Crocodiles eat any animal food to be found in water or ashore. They usually eat fish and small animals and birds floating on water. The largest crocodile species prefer not to waste time on trifles: they lie in wait for large animals that come to drink water, such as buffaloes, zebras, and antelopes.