The reptiles are vertebrate animals which can live in terrestrial environment. They are thus able to move on ground or in water to provide for their needs. It is in fact the first animals which at the time of prehistory left water and populated terrestrial spaces of the earth.
The reptiles lay eggs whose shell resists the air and enabling them not to have to make the laying in water like the amphibians. Their skin is as effective against drying as the exposure to the air and is made scales like the snakes.
The capacity of the reptile to live on solid ground is that it breathes and it must thus go up out of water to take its breath. The tortoises, snakes, lizards and crocodiles are reptiles.
The reptiles, like the snakes, molts or they lose their old skin and thus they can grow bigger. The tortoises and crocodiles really do not molt because it is an enlarging of their scales which enables them to grow bigger.
Many reptiles use their tail as means of defense like the lizards. Others nothing but do hide in their shell like the tortoises, but those have also a frightening bite. The crocodiles and alligators are the predatory reptiles and their skin is very rigid. Their mouths are lengthened and equipped with pointed teeth.
Many reptiles are exclusively carnivorous as the crocodile which eats only meat. Some eat fruits, insects like the tortoises and the lizards.
Many people use a reptile as pet. The tortoise and certain lizards are very popular like domestic animals and the sale of reptiles is regulated in many countries.
