Nearly 5,000 species of frogs live on every continent in the world except Antarctica, with the highest concentration found in tropical zones, says the Defenders of Wildlife. Frogs are amphibious, meaning they live on land and in water, where they begin their lives as tadpoles. Frogs species vary among ecosystems, but all frogs use their vocal abilities to declare their territory and to attract mates. Frogs peep, hammer, croak, tap, saw, thonk, trill, thump, rasp, click, yodel; some even sound like they are screaming.
Spring peepers herald the arrival of spring, emitting a high-pitched sound that resembles a scream. These small frogs reside in the woods and around ponds and swamps in the United States and Canada. They blend into their surroundings and are brown with "dark lines that form a telltale 'X' on their backs," says the National Geographic website. They use their sticky toe pads to climb trees, where they call at night.
The coqui frog is native to Puerto Rico. Its scream-like cry resembles the sound of its name. This very small frog (34 to 41mm long) is grayish with big red eyes. They live mostly in trees and prefer moist environments, where they sing from dusk until dawn. The coqui frog differs from most frogs in two ways: the male guards the eggs, which hatch not into tadpoles but emerge as fully formed young frogs.
Eastern Gray Treefrog
The Eastern gray treefrog has a soft screaming cry, almost as if it was pretending to be scared. These 3-inch frogs can change colors instantly, from bright green to gray, an effective ploy with which to evade predators. They prefer wooded areas, climbing high into the trees using their sticky toe disks and calling to each other. Like several other frog species, they have the ability to survive over the winter by changing the chemical composition of their blood.
Green and Black Poison Dart Frog
The green and black poison dart frog has a thin, high call that sounds like a distant scream. This frog is native to the rain forests of Central and South America and were introduced by humans to Hawai'i. Their skin is toxic, which is an effective way to discourage predators. Indigenous people traditionally have used the toxin of this and other poison dart frogs to tip their spears with before hunting. The toxin causes almost instant paralysis and death.