The life cycle of a frog starts when a female frog lays some round, gelatin eggs in the water of a nearby lake or pond. In this pond, the eggs are attacked by many predators such as fish and sometimes even other frogs.
If a tadpole is lucky enough to get out of the egg by eating it, they have to survive cannibalism. The tadpoles can survive underwater using their gills, which they grow out of once they lose their tails. Many of the stronger tadpoles will sometimes eat the weaker ones to survive. Some of the tadpoles' own parents will eat them if they are short on food.
If the tadpoles survive long enough to grow their front legs, they can swim around faster, thus making it easier for them to survive. Then they will grow their back legs and lose their tails, and leave the water.
After leaving the water, the baby frog will eat flies and other small insects, until it grows older, and mates, then the life cycle starts over again.