Dolphins are social creatures that seem to have a particular affinity with humans. Many people have found swimming with dolphins to be a life-changing experience and this is often used as therapy for very sick children. Even seen from a boat dolphins seem so happy and carefree, their only concern, where the next meal is coming from. There are countless tales of how these aquatic mamals have helped people who would have otherwise drowned.

Dolphin groups called pods often cooperate in hunting. They encircle a large shoal of fish, force the fish into a smaller and smaller group, then take turns to charge through the mass of fish.

They can be found in most non-arctic waters and eat a varied diet that includes fish, squid and shellfish. Fish are swallowed whole, head first so that the bones do not stick in the dolphin's throat.

Dolphins are warm-blooded. This means that they must eat enough to provide enough fuel for the respiration that keeps their bodies around 37 degrees Celsius. They consume about 5% of their body weight in food each day. A nursing mother may consume up to 8%. Dolphin calves are born alive, either head first or tail first. The mother produces milk for them in the same way as all female mammals do. The calves are about 4 feet long at birth and darker in color than adult dolphins.

Dolphins have excellent hearing and can detect sound at frequencies far below human hearing as well as sounds far, far above the highest frequencies we can detect. They can localize sounds underwater, something else that humans cannot do. Dolphins' eyesight is also excellent both in water and in air. Their eyes are well adapted to dim light but they see well in bright light too. Dolphins are hunters and have binocular vision in water and in air. Dolphins have a limited sense of smell, but their skin is extremely sensitive.

Dolphins normally swim at around 5 mph but can reach speeds of 20 mph for short times.