A frog is classified as an amphibian. Amphibians can live on land and in fresh water. Frogs also lay eggs in water, and their eggs eventually hatch into tadpoles. A tadpole lives in water until it changes into a frog.
Frogs breathe through their nostrils and skin. They also use their skin to soak up water, rather than drink it. If a frog's skin dries out, it will die. So, although frogs can live on land, they must live near swamps or ponds so they can keep their skin moist.
Frogs can see everywhere at the same time--forward, sideways and upward. They also never close their eyes. Frogs can even use their eyes to help them swallow food. When a frog blinks, its eyeballs push downward and create a bump in the roof of its mouth. The bump squeezes against any food inside the frog's mouth and pushes it down the throat.
Frogs use their tongues to capture food. A frog's tongue is attached to the front of the mouth. This allows the frog to stick its tongue out far enough to catch food. Frogs eat insects, snails and worms. Larger frogs can also eat fish, small reptiles and mice.
Frogs and toads aren't the same, although they are closely related. Frogs look different from toads, but the main difference is that toads spend more time on land. Toads have adapted to living out of water for a while, but frogs need to spend at least part of their time soaking in water.