All dolphins live in groups called "pods". They are social animals at all stages of their life. They have some remarkable behaviours. A speeding group of dolphins is a sight to see. They "porpoise" in and out of the water at high speed. The function of this is not known for sure. It may be the fastest movement they are capable of. What they eat, almost exclusively, is fish. When they chase fish, the fish go into a "bait ball" to self-protect. In turn, the dolphins attack in a group and eat as many fish as they can.