They also are amphibians. When warm weather comes, most female frogs lay their eggs in the water. When the dry weather comes the bull frog buries itself in the mud in the bottom of the pond and comes out when the weather gets warm again.
Tadpoles breathe through gills.
When it grows up, it breathes through lungs. But before the tadpole gets its grown up lungs, it has to kind of suck in its gills. Frogs do not drink water the way we do. They drink by absorbing water through their skin. They also lose water through their skin.