Because there are so many animals, scientists have grouped them into categories so that they can be studied more easily. Remember, however, that there are always exceptions to any rule. Here is a simplified breakdown.
Amphibians have backbones, are cold-blooded, and live on land and in water at different times.
Three types of amphibians are frogs and toads, salamanders, and caecilians. Caecilians are primitive amphibians that resemble earthworms. They are found in the tropics. By definition, an animal is a living thing that can move, obtain food, rid itself of waste, and reproduce. Cold-blooded animals depend on their surroundings to establish their body temperatures .