Turtles like to eat fish, jellyfish, carrion and plant material. Other things turtles like to eat are small aquatic animals, such as frogs and salamanders. Some eat worms, insects and crustaceans. A turtle such as the common snapping turtle is omnivorous, eating both plant and animal material.
The diets of some turtles change as they get older. This is typical of the green turtle, a large marine turtle. When green turtles hatch and make their way to the sea, they eat plankton, which are tiny animals borne along by the ocean currents. They also eat jellyfish, crabs and other small marine animals. As they grow, they move inland and start to eat sea grass and other vegetation. By the time they're adults, green turtles are completely herbivorous.
Box turtles also alter their diet as they grow older. When they're young, they are omnivorous and eat nearly anything, including dead birds and dead mammals as large as a cow. Adult box turtles mostly eat vegetation, but not green leaves. They are partial to fungi and fruit.
Because much of its diet includes crustaceans and mollusks, the northern map turtle, especially the female, has evolved a mouth that is stronger than those of other turtles of their species.