dult crocodiles feed on crustaceans, fish, small mammals, and water birds; the young feed on frogs and small insects. Adults approach a swimming animal from under water and drag it down until it drowns. Crocodiles do not chew their food; if their prey is too large to be swallowed whole, they grasp it with their teeth and twist their bodies in order to tear chunks of flesh from it. According to a medieval fable, the crocodile sheds tears for its victims as it devours them. Thus the expression "crocodile tears" refers to false sympathy.The female builds a nest of sand, sticks, and vegetation. The mound of material is usually one foot (30 cm) high and 10 feet (3 m) long. She lays 20 to 60 white eggs in the nest and incubates them for three months. After the young hatch, the mother carries them in her mouth to the nearest body of water. The young are eight to nine inches (20 to 23 cm) long at birth. They mature in five years.