Bullfrog

The American bullfrog is a big, chunky frog with smooth green and brown skin. It is the largest true frog in North America, and an exceptionally large one can reach about 20 centimetres long. Behind each eye is a round patch called an eardrum, and on the males this patch is even bigger than the eye itself.

Bullfrogs love the water and are almost always found close to a pond, lake, marsh, or slow river. They come from the eastern half of North America, from Canada down to Florida. They like warm, still, shallow water where they can float with just their eyes and nose poking out.

These frogs are not fussy eaters. A bullfrog will sit very still and wait, then snap up almost any small creature that comes near, such as insects, worms, snails, little fish, and even other frogs. Waiting quietly and grabbing a meal as it passes is called being an ambush hunter.

A bullfrog's life begins in the water as an egg, and then as a tadpole. The tadpoles are large and can take a year or more before they change into little frogs with legs, a journey called metamorphosis. In summer the males float in the pond and make their deep, booming calls to tell other frogs where they are.

Because bullfrogs are big and tasty, people have carried them to many places far from their home, including parts of Europe, Asia, and South America. In these new places they are called an invasive species, which means they were not there naturally and can eat or crowd out the local frogs and other small animals. Scientists and rangers keep an eye on where they spread.

In their natural home there are still lots of bullfrogs, so they are not in danger. The main things that help them everywhere are clean water and healthy wetlands where frogs of all kinds can grow up safely.