They hop, they jump, some of them stick to windows - frogs!
Frogs come in many different shapes, sizes, and colors, and can be found almost anywhere
in the world.
Add to that one of the most interesting life cycles on earth, and it's no wonder that people
everywhere are fascinated by frogs.
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With their short, smooth bodies, bulging eyes, and webbed feet tucked neatly underneath,
frogs are easily recognized.
They are often green, or brown, but are sometimes brightly colored instead.
Some drier, bumpier specimens, like this little fellow, are called toads, but toads are actually
part of the frog family too.
Frogs are predators, and eat many kinds of insects as well as invertebrates like slugs,
snails, and worms.
Their large eyes are very sensitive to movement and help them locate their prey.
Once spotted, its meal has little chance to escape.
In less than a second, the frog's long, sticky tongue flicks out of its mouth, sticks to
its prey, and rolls back into the frog's mouth.
So long, worm!
Although we often see them on land, frogs are most at home in the water - and the reason
for that is in their biology.
Frogs are amphibians, or small vertebrates that rely on a wet environment to survive.
With more than 7,000 known species of frog, they make up 88% of all known amphibians.
Unlike fish, which must stay in the water to breathe, amphibians have lungs and can
collect their oxygen from the air - but they do it in a peculiar way.
Frogs can breathe through their skin.
As long as their thin, delicate skin stays moist, oxygen from the air can pass directly
through it into their bloodstream.
If necessary, they can breathe through their nose and mouth, but compared to us, their
lungs are poorly developed and breathing this way is just not efficient.
If a frog gets too dry, it can die from lack of oxygen.
For this reason, few frogs will stray too far from a source of water.
This special skin allows frogs to breathe underwater as well.
Frogs can stay underwater for hours at a time under normal conditions.
During hibernation, when their body slows down, some frogs may stay underwater for months.
Frogs can be found on every continent except for Antarctica.
Like reptiles, they are cold-blooded, and rely on their environment to maintain their
body temperature.
With very rare exceptions, frogs cannot survive in salty water or desert conditions.
Although some frogs have adapted to survive freezing winters, most species of frogs live
in tropical rainforests.
Some of these frogs, native to tropical Central and South America, have a special ability.
They are called poison dart frogs, and they are among the most poisonous living creatures
on earth.
They are small, even for frogs.
Some of the smallest are only about half an inch or one centimeter in length, about the
size of a thumbnail.
The largest are only about 2.4 inches or 6 centimeters long.
There are more than 100 different species of these frogs.
Poison dart frogs secrete toxins through their skin.
If a predator eats or sometimes only touches one of these frogs, it can get sick and die.
Their bright colors and bold patterns shout a warning to would-be predators: don't eat me!
I'm poisonous!
Even less brightly colored frogs capture our attention for another reason; they are famous
for their fascinating life cycle.
Every frog begins as an egg.
Frogs' eggs do not have a shell, like the eggs of birds or reptiles.
Instead, these eggs, called frogspawn, have a jellylike appearance.
With no shell to keep them from drying out, frog eggs must be kept moist.
As a result, they are usually laid in slow moving fresh water, but can also be laid on leaves,
in swamps, or in foamy nests.
After a few weeks, the eggs hatch, producing young that look very different than their parents.
They are called tadpoles, and right now they look more like fish than frogs.
They are similar to fish in some ways; they have gills and must stay in the water to breathe
until their lungs develop.
Over the next few months they will grow legs, develop lungs, lose their tails, and begin
to explore the world outside their watery homes.
This change is called metamorphosis, meaning a transformation.
Once the tadpoles have completed their transformation into frogs, they are free to explore dry land
- as long as it's not TOO dry.
Due to their small size and general harmlessness, frogs are popular with people looking to observe
nature a bit more closely.
Some people even keep frogs as pets.
If you're ready to go look for frogs where you live, check carefully around ponds, streams,
or other bodies of fresh water.
Unfortunately, these fascinating amphibians are under threat.
Pollution and loss of habitat may drive many species of frogs to extinction.
If you want to help frogs, make sure that you do not use pesticides or other chemicals
in your yard.
Add native plants that can give frogs places to hide and attract the insects that they love
to eat.
And, if you really want more frogs in your yard, you can add a small frog pond to give
them a place to live.
I hope you enjoyed learning about frogs today.
Goodbye till next time!