The most common and well known type is the bottle nose dolphin. We tend to think of the Orca/killer whale as a type of whale, but they are actually part of the dolphin family.
Dolphins are very intelligent and besides from being able to learn tricks, they are also known for saving people from danger and are also very playful and entertaining. Even out in the wild, they will entertain themselves through play. Some people call them the 'angels of the sea' since they have been known for helping other animals and humans.
They are carnivores, which mean they eat meat. They hunt in groups (which is called a 'pod') and can eat large schools of fish at one time. They swim through the school of fish and confuse and scare the fish so much that it is easy for them to catch the fish.
They are social animals and the move together in their pods. Some pods are smaller than others, but it is very seldom that dolphin prefer being by themselves.
Dolphins can stay under water for a period of time, but they need to come to the surface to breathe in oxygen. They use a blowhole for this. They also have excellent sight and smell and they locate fish and objects under water through something called 'echolocation'. They send out sound waves that bumps against the object and is send back to the dolphin. That way the dolphin can find an object.
Some dolphin species face the threat of extinction, often directly as a result of human behavior. The Yangtze River Dolphin is an example of a dolphin species which may have recently become extinct.
