Breathing is often accompanied by a low hissing or puffing noise. The Delphinidae include the most agile and some of the most speedy cetaceans. They commonly surface several times a minute and frequently leap clear of the water. Many species follow ships and seem to frolic about the bow. They have remarkable group precision and regularity of movement.
Migration is known to occur in some species.
The sense of vision is not as well developed as that of hearing, but Tursiops can see moving objects in the air at least 15 meters away. Observations of captive dolphins indicate that these animals are very intelligent. Adult delphinids will engage in complex play with various objects and can be trained to perform tricks. Dolphins and porpoises usually associate in schools of five to several hundred individuals, though they are sometimes seen alone or in pairs. Groups may assemble when frightened and will attack intruders.