However, when fish begin migrating or are scarce, dolphins become nocturnal hunters. They search for squid and bottom-dwelling fish which are active at night. Dolphins are very sociable animals that generally live in groups. Their friendly, cooperative behavior is vital to their survival. When a dolphin is sick or injured, it cries of distress summon immediate aid from other dolphins, who try to suppoert it to the surface so that it can breathe.
Dolphins spend a large part of the day playing.
Dolphins communicate by means of high-pitched whistles and clicks which create sound waves. The sound waves travel through the water and bounce off solid objects, causing an echo. A dolphin's brain is adapted to understand the echoes that travel through the water. Coastal waters of the Atlantic, the temperate North pacific and the Red Sea and Indo-Pacific region are home to three species of bottlenose dolphin. Tursiops truncatus trucatus, T.t. gilli, and T.t. aduncus respectively.