The dolphin is one of the most intelligent and playful animals on our planet. Dolphins often display a playful attitude which makes them popular in human culture. They are very social animals. They are mammals just like you and I. Dolphins breath air, give birth to live young, nurse their babies with milk, and have a constant body temperature like warm blooded animal. Most dolphin species live in the sea water and can be found in all oceans of the world, and just a few species live in the fresh water of Asia and South America. Even though dolphins spend their whole lives in the water, they are not fish, but are mammals. It is interesting to know that Dolphins can't breathe water like fish, but they need to come to the surface to breath air.