Frogs evolved over 200 million years ago. They live in virtually every climate from extremely dry deserts to perpetually wet marshlands. To grow, frogs shed their skin—most species about once per week. They eat the shed skin.

The male Darwin frog swallows its babies immediately after they emerge from the tadpole stage, holding them in his vocal sac for 2 months until they are ready to survive on their own.

Over 6,700 species of frogs have been identified, and of those, 23% are threatened with extinction.