Frogs
A Frog is a small, tail less animal that has bulging eyes. Almost all
frogs have long back legs. The strong hind legs make the frog able to leap
farther than the length of its body. Frogs live on every continent except

Antarctica, but tropical regions have the greatest number of species. Frogs are
classified as amphibians. Most amphibians, including most frogs, spend part of
their life as a water animal and part as a land animal. Frogs are related to
toads, but are different from them in a few ways. The giant frog of west-central

Africa ranks as the largest frog. It measures nearly a foot (30 centimeters)
long. The smallest species grow only 1/2 inch (1.3 centimeters) long. Frogs also
differ in color. Most kinds are green or brown, but some have colorful markings.

Although different species may vary in size or color, almost all frogs have the
same basic body structure. They have large hind legs, short front legs, and a
flat head and body with no neck. Adult frogs have no tail, though one North

American species has a short, tail like structure. Most frogs have a sticky
tongue attached to the front part of the mouth. They can rapidly flip out the
tongue to capture prey. Frogs have such internal organs as a heart, liver,
lungs, and kidneys. Some of the internal organs differ from those of higher
animals. A frog\'s heart has three chambers instead of four. And although adult
frogs breathe by means of lungs, they also breathe through their skin. The eggs
of different species vary in size, color, and shape. A jelly like substance
covers frog eggs, providing a protective coating. This jelly also differs from
species to species. Some species of frogs lay several thousand eggs at a time.

But only a few of these eggs develop into adult frogs. Ducks, fish, insects, and
other water creatures eat many of the eggs. Even if the eggs hatch, the tadpoles
also face the danger of being eaten by larger water animals. The pond or stream
in which the eggs were laid sometimes dries up. As a result, the tadpoles die.

Certain tropical frogs lay their eggs in rain water that collects among the
leaves of plants or in holes in trees. Other tropical species attach their eggs
to the underside of leaves that grow over water. When the eggs hatch, the
tadpoles fall into the water. Among some species, one of the parents carries the
eggs until they hatch. For example, the female of certain South American tree
frogs carries the eggs on her back. Among another species of frog, the midwife
toad, the male carries the eggs wound around his hind legs. Males of another
species, Darwin\'s frog, carry the eggs in their vocal pouch. Some tropical frogs
lay their eggs on land. They lay them under logs or dead leaves. These frogs
have no tadpole stage. A young frog hatches from the egg and begins life as a
land animal. Tadpoles are not completely developed when they hatch. At first,
the tadpole clings to some support in the water, using its mouth or a tiny
sucker. A tadpole has no neck, and so its head and body look like one round
form. The animal has a long tail and resembles a little fish. It breathes by
means of gills, which are hidden by a covering of skin. A tadpole\'s form changes
as the animal grows. The tail becomes larger and makes it possible for the
animal to swim about to obtain food. Tadpoles eat plants and decaying animal
matter. Some tadpoles eat frog eggs and other tadpoles. In time, the tadpole
begins to grow legs. The hind legs appear first. Then the lungs begin to develop
and the front legs appear. The digestive system changes, enabling the frog that
develops to eat live animals. Just before its change into a frog, the tadpole
loses its gills. Finally, a tiny frog, still bearing a stump of a tail, comes up
from the water. Eventually, the animal absorbs its tail and assumes its adult
form. After a frog becomes an adult, it may take a few months to a few years
before the animal is mature enough to breed. The green frog and the pickerel
frog mature in about three years. In captivity, a bullfrog may live more than 15
years. But few species of frogs live longer than 6 to 8 years in the wild. Many
are eaten by such enemies as bats, herons, raccoons, snakes, turtles, and fish.

Adult frogs eat mainly insects and