Approximately 4,740 species of frogs exist in the world. Frogs are found on all continents except for Antarctica. More than 120 species of frogs have become extinct since 1980.
More than 90 species of frogs live in the United States. Frogs have a variety of skin colors, bone formations and sound capabilities. Most frogs species live in warm, sub-tropical climates. The population of frogs is a bio-indicator of the health of an ecosystem. With frogs taking on the role of both predator and prey, many animals are affected by even the slightest change in frog populations. While most frogs are born in the water as tadpoles, some frogs are born fully developed, allowing them to live in places with little access to water, such as mountaintops.