They drive the fish into a dense mass and force them to the surface of the water, making it impossible for the fish to escape. The also emit loud sounds to further confuse the prey. Dolphins usually hunt during the day. 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.