Frogs go through a complete metamorphosis, which has four stages: egg, tadpole, froglet, and frog. During these stages, the frog goes from living in the water to living on the land.
Frogs start as eggs that float on the surface of the water. These clusters of eggs are called “egg masses”. A frog can lay up to 4,000 eggs at one time.
The next stage is the tadpole stage. Tadpoles hatch from the eggs and live in the water. They have a large head and a tail. They have gills and live completely submerged in the water similar to a fish.
As a tadpole grows, it becomes a froglet. The body shrinks and legs form. A froglet still has its tail.
As the tail shrinks and the lungs develop, a froglet becomes a full-fledged frog, which begins living land instead of in the water.