My Science School

Sometimes it is hard to tell whether an animal is a lizard or not. Some lizards look like snakes, and some look a lot like worms.

There are three things that all lizards have. They all have eyelids that close, ears on their heads, and long tails. Most lizards also have four legs. But a few lizards, such as glass snakes and slow worms, have no legs at all.

Lizards are reptiles that live on the ground or in trees. Most live in warm, tropical regions, but some live in areas with cold winters. A lizard’s scaly skin helps keep moisture inside its body even when the weather is very hot.

Like other reptiles, lizards are cold-blooded. But like some warm-blooded animals, some lizards hibernate, or sleep through the cold winter months.

Picture Credit : Google

Snakes have no legs at all, but they move very well without them! A snake can zigzag over the ground just about as fast as most people can walk.

Snakes are different from lizards because they have no ears and no eyelids. And to smell, a snake flicks out its tongue! Snakes use their good sense of smell to find their food.

Most snakes like their food alive. They eat many kinds of small animals - even other snakes. Snakes don’t chew their food - they swallow it whole. Their jaws are hinged like a pair of nutcrackers. For a great big mouthful, they can release the hinges and open their mouths very wide. In fact, a little garden snake can swallow a whole frog! The African egg-eating snake can swallow an egg bigger than its own head. And a big python can swallow a whole pig, hoofs and all!

Pythons curl themselves around their prey and squeeze it to death. Other snakes, such as vipers and rattlesnakes, have poison glands. Hollow teeth, or fangs, inject the poison into the victim’s body. Some kinds of cobras squirt poison at an attacker’s eye.

Picture Credit : Google

Turtles and tortoises are reptiles with shells on their backs. Most can pull their heads, legs, and tails inside the shell for protection.

Many turtles spend a lot of time in the water. They can swim much better than they can walk. The sea turtle spends almost all its time in the water and has strong flippers for swimming. These turtles eat animals and plants.

Tortoises are turtles that live only on land. They have club-like legs for walking on sand, mud, or grass. The shells of most tortoises are tall and round, while the shells of many other turtles are flat to help them glide through water. Most tortoises eat plants.

Turtles don’t watch over their eggs before they hatch. Female turtles dig holes in the mud or sand. They lay their eggs in the holes, then cover up the eggs and go away. The warm sun hatches the eggs, and the babies dig their own way out.

Picture Credit : Google

It’s the middle of the night in the desert. A small lizard lies almost covered with sand. Only its head sticks out. It is using the sand like a blanket to keep its body warm during the cool night.

When the sun comes up, the lizard crawls out of the sand. It moves very slowly because it is still cold. It lies on a rock for a long time, letting the sun warm it. When its body is warm enough, the lizard dashes off to look for food.

Lizards and all other reptiles are cold-blooded. Their bodies get just as hot or cold as the air or water around them. If their bodies get cold, reptiles can’t move well. If they get too hot, reptiles die. So reptiles must spend their time playing hide-and-seek with the sun. If they are cold, they lie in warm sunshine. If they are hot, they hurry into the shade.

A reptile that lives where winters are cold moves more and more slowly as cold weather comes. The reptile curls up in the warmest hole it can find. Soon its body grows cold and stiff. It cannot move at all. Only when warm weather returns can the reptile move again.

Picture Credit : Google

Have you ever seen a big, fat frog? Did its bulging eyes and raspy croak make you laugh?

Have you ever seen a tiny garden snake zipping through the grass? Were you amazed at how fast it could travel with no feet?

Snakes and frogs belong to two groups of animals called reptiles and amphibians.

Amphibians and reptiles slither, scamper, hop, or swim. Some hiss, some croak, and some make no sound at all. Some amphibians have scaly skin that feels like tree bark. Some snakes have skin that feels like warm glass. Some frogs are slimy, but most snakes are not.

Amphibians and reptiles live all over the world - in woodland forests and rain forests, the Australian outback and the African plains, and maybe in your own garden.

Picture Credit : Google

Suppose you found some eggs lying on the ground. Now suppose that some little creatures with scales hatched out of them. What kind of animal would they be?

Could they be fish? Fish have scaly skin, but fish eggs do not have hard shells. Besides, most fish lay their eggs in water. So they could not be fish.

Could they be birds? Birds lay eggs, too. But birds don’t have such scaly skin. So they could not be birds.

They must be reptiles. Only reptiles have scaly skin and lay their eggs on land. Alligators, crocodiles, lizards, snakes, turtles, and tuataras are all reptiles.

Picture Credit : Google

Did you ever swim wearing flippers? If so, you know that they help you swim faster. Flippers are like the webbed feet of ducks, geese, and swans. Webbed feet are like paddles. They push lots of water, so the bird can move faster.

Ducks, geese, and swans are all waterfowl. They spend most of their time in lakes, ponds, rivers, or the sea.

Different kinds of waterfowl have different ways of getting their food. Some kinds of ducks, such as mallards, wigeons, and teals, are known as dabbling ducks. To get food - water insects, snails, and water plants - a dabbling duck puts its head underwater. Its feet and tail stick straight up in the air. Swans feed this way too, but they eat mostly plants.

Ducks such as pochards, canvasbacks, and grebes are known as diving ducks. They dive underwater and eat mostly water plants.

Geese usually feed on land. They like grass, seeds, and plants. Their bills can clip off the tops of plants as neatly as a pair of scissors.

Colourful mandarin ducks often perch in trees when they aren’t swimming.

Picture Credit : Google

Would you be able to grasp a tree branch with your toes and then fall asleep, without falling? No, because your feet are not made for living in trees.

Birds have feet that suit their way of life. Birds that perch on branches have toes that curl around the branch to give a tight grip. The grip is so tight that the bird doesn’t fall off even when it sleeps.

Birds that find their food in the ground have short, blunt toes like tiny rakes. They scratch the ground to turn up insects and seeds. Ducks, geese, and swans have feet like paddles to help them swim in water. Birds of prey, which eat small animals, have sharp, curved claws - just right for grabbing the creatures they hunt.

Climbing birds, like parrots and woodpeckers, have two toes pointing forwards and two toes pointing backwards. Cassowaries and most other fast-running birds have three toes on each foot.

Picture Credit : Google

A baby swift is getting ready to fly. Ever since it hatched, its feathers have been getting longer. Its wings have been growing stronger. Now, the little bird is ready.

It hops to the edge of the nest. Even though it has never flown, the swift knows just what to do. It spreads its wings and pushes itself off the nest with its legs. Air pushes up on the swift’s wings and holds the little bird up. The swift begins to flap its wings. Feathers on the ends of the wings spread out and twist. This pulls air under each wing and pulls the swift forwards.

Now the little swift is tired. It lands by spreading out its wings and tail as a brake. Many birds can fly the very first time they try. Some birds, such as sparrows, need a little practice. They flutter weakly out of the nest. Before they can really fly, they hop about on the ground, flapping their wings for a few days.

Picture Credit : Google

Snoring is nothing but the sound produced by the vibration of certain parts in the upper airways. When we sleep, our body muscles, including those in the upper airways, relax and the soft tissues such as the tongue, soft palate, uvula and tonsillar pillars become slack. Sometimes they relax so much that the upper respiratory tract partly closes and becomes too narrow for enough air to travel through to the lungs. When we inhale, the air hits these respiratory structures, causing them to vibrate and create the turbulent sound we call snore. The narrower the airway, the louder the snoring.

Anything that prevents you from breathing through your nose can cause you to snore. This can include congestion from a cold and allergies. Those who have enlarged tonsils, an enlarged tongue or excess weight around the neck are more prone to snoring.

Normal ageing can also relax your throat and tongue muscles, causing snoring. Snoring is also a symptom of sleep apnoea, a potentially serious sleep disorder in which breathing repeatedly stops and starts.

 

Picture Credit : Google