Echoes are produced when the sounds reflect from an object in front of the dolphin. By listening to the echoes, the animal determines the location of the object. Most kinds of dolphins have a large number of teeth. Some species have more than 200. Dolphins use their teeth only to grasp their prey, which are chiefly fish and octopuslike animals called squids.
Dolphins swallow their food whole and usually eat the prey headfirst.
The life of dolphins Most dolphins mate in spring and early summer. The males are called bulls, and the females are called cows. The courtship behavior may involve head-bumping. The pregnancy period for most species of dolphins lasts from 10 to 12 months. The females almost always give birth to one baby, called a calf, at a time.