Human Eye - How The Eye Works and What are Rods and Cones?

Your eyes are like two tiny movie cameras inside your head.
They are sending a steady stream of pictures back to your brain, like a television camera sending live pictures back to a TV screen.
Human Eye
Your eyes have a part called the lens, just like a camera. The lens helps to bring everything you look at into focus, so that details are as clear as possible.

What are Rods and Cones?

Human beings are luckier than many other animals because they see in color. Some other animals, such as birds and butterflies, can also see colors.
To see colors, we have special cells in the eye called cones. 
They share the work of seeing with other cells called rods.
Rods do not detect the difference between colors and don’t need as much light as cones to make them work.
So at times, rods are more useful to you than cones, such as at night when the light is very dim.
Have you ever been for a walk in the moonlight and noticed how pale, silvery, and colorless everything seems?
Photographers can take pictures by moonlight which are just as colorful as pictures taken by day. So the colors are still there by moonlight, but we can’t see them.
Can you think why this is?
The cones help us to see color, but moonlight doesn’t provide them with enough light to function well at night.
What are Rods and Cones

 What Is Stereoscopic Vision?

When we use both our eyes, we have a kind of sight called stereoscopic vision. 
Because both eyes are at the front, they both see the same object. But your eyes are a little apart from each other, so each has a slightly different view of things. 
You can check this if you place two objects, such as drinking glasses, on a table in front of you. 
Place one about 8 inches (20 centimeters) away from you, the other 2 feet (60 centimeters) away. 
Put your chin on the table with the two glasses in a straight line away from you. 
Close one eye, then the other. 
Do you see exactly the same thing with both eyes?
Your brain makes use of the fact that your eyes tell different stories. 
By comparing the messages from each eye, your brain works out how far away an object is. 
Your brain does this in a split second every time you look at anything.

Stereoscopic Vision Test for kids

Why are our eyes on the front of our head, both looking the same way? 
It seems a waste of an eye, doesn’t it? 
To discover the answer, play this game of throwing and catching a ball with a friend.

You will need:
  • stiff, black paper or cloth
  • scissors
  • a sharp pencil
  • a ball
  • thin elastic or ribbon
Stereoscopic Vision Test for kids

1.Cut out an eyepatch from the paper or cloth. Using the pencil point, make a small hole on either side of the patch. Thread the elastic or ribbon through the patch.
2. Play at catching the ball with both eyes first. Throw the ball 20 times, and make a record of how often you drop the ball.
3. Now cover one eye with your patch. Keep a record for another 20 catches. Did you do as well? Explain what happened.

How does the Human Ear Work? - The Human Body for Kids

How does the Human Ear Work? - The Human Body for Kids

How does the Human Ear Work
Your ears are organs.
They aren’t just the flaps of skin you can see!
Your ears stretch deep into the skull.
They do a very important job.
They collect sound waves, which are tiny vibrations of air, and change them into signals that your brain can understand.
To do the difficult job of hearing, the ear has three different parts.
These are called the outer ear, the middle ear, and the inner ear.

What does the Outer Ear Do?

The outer ear consists of the ear flap, which is the part you can see, and a hollow tube, called the ear canal. This leads to the eardrum.
The eardrum is made of a sheet of skinlike material called a membrane.
This vibrates when sound waves travel down the ear canal.

What does the Middle Ear Do?

The middle ear is like a hollow cave.
It contains three bones, called the hammer, the anvil, and the stirrup. 
When the eardrum vibrates, it makes the hammer vibrate. This movement is passed on to the anvil and then to the stirrup.
The stirrup makes another membrane, called the oval window, vibrate.

What does the Inner Ear Do?

Behind the oval window is the inner ear. This is made up of the cochlea, the vestibule, and the semicircular canals. 
The cochlea has three tubes, which are coiled like a snail’s shell. These tubes are filled with fluid. When the oval window vibrates, it makes waves in the fluid.
One of the tubes has thousands of sensitive hairs.
When the fluid passes over the hairs, it prompts your nerves to carry messages about sound to your brain.

Vestibular System and Human Balance

The semicircular canals help you keep your balance.
They also contain fluid and sensitive hairs.
If you tip your head to one side, the fluid in these tubes moves, and the sensitive hairs let the brain know what has happened.
The vestibule is a chamber between the canals and the cochlea. 
It contains two sacs, also filled with fluid and sensitive hair cells.
The sacs have chalky particles inside them, which are pulled to the earth by the force of gravity. When you stand upright, the particles press on the hairs at the bottom of each sac.
When you lie down, the particles settle to one side and press on a different set of hairs.
Nerves from the hairs signal your brain about the position of your body.

What are the Five Senses? - The Human Body for Kids

Sense organs are specially developed parts of your body.
For example, each of your eyes has a retina for detecting light.
And each of your ears has a cochlea for detecting sounds.

Can you name the “five senses”? 

Try to name them before reading further.
These senses send information to the brain.
There are special parts in the brain that sort out this information.
It is then passed to other parts of the brain, which can compare information from different sense organs. Your brain then signals what you are:
  • seeing, 
  • hearing, 
  • smelling, 
  • tasting, and 
  • touching. 
These five senses allow you to know what is in your physical environment.
What are the Five Senses
What are the Five Senses?

The hidden senses

Another set of senses, of which you are unaware of most of the time, helps control your inner organs. 
These senses control the timing and movement of food through your body.
They measure the amount of sugar and salt in your blood.
They regulate the amount of oxygen that’s taken in.
Your body temperature and the fullness of your bladder are also under the control of these senses.
Without your awareness, your body is always receiving messages from your hidden senses.
They keep all these basic processes, such as breathing and digestion, running smoothly.

Where Are Your Kidneys Located? - The Human Body for Kids

What do Kidneys do?

Your kidneys make the waste liquid your body has to get rid of.
You have two kidneys, one on each side of your spine, behind your stomach.
They are shaped like beans and are nearly as large as your heart.
Your kidneys filter your blood as it travels through them.
Where Are Your Kidneys Located? - The Human Body for Kids
Kidneys take out waste products that your blood has carried away from all the cells.
One of the main waste products is called urea. This is made after your cells have broken down substances called proteins. 
Kidneys also take away some salt and water from your blood if it contains too much of them. Your body must keep a balance of salt and water. Keeping this balance is the responsibility of the kidneys.
Your kidneys then get rid of the water and waste products by making droplets of a liquid called urine. 
The urine passes into your bladder through two tubes called ureters. 
Your bladder is a bag made of muscle, which stretches as it fills with urine.
When you decide it’s time to expel the urine, the bladder squeezes it out through a tube called the urethra.
Where Are Your Kidneys Located? - The Human Body for Kids

Digestive System For Kids - How does the Digestive System Work?

What is digestion?

When you eat, your food begins a long journey through your body.
Most of your food is broken down into lots of tiny, simple pieces so that your body can use it.
This breaking- down process starts in your mouth and is called digestion. 
The various substances that aid in digestion are known as digestive juices.
Your body uses food to acquire energy. Food contains special chemicals that provide energy in your body’s cells.
Energy keeps all the different parts of your body working.
Without energy, all your muscles and every other part of you would stop working.
Food also helps your body grow and repair parts that have become worn out or damaged.

Food to keep you healthy

Food contains many different substances that work together to keep you going.
Food substances that give you energy are called carbohydrates and fats. Carbohydrates are found in foods like potatoes, rice, and bread. Milk, butter, and cheese are fatty foods.
The parts of your food that help your body grow and mend itself are called proteins. These are mainly found in meat, milk, eggs, nuts, and grain.
Your food also contains vitamins and minerals, which help you stay healthy. They make the chemicals in your body work properly.
Food also contains tough parts called fiber. Fiber helps to keep your intestines in good working order.
We take in water from our food, as well as water from what we drink.
Your blood needs a great deal of water to carry all these substances around your body.
Digestive System For Kids - How does the Digestive System Work?

Food Digestion Process

1. Your food is mixed and mashed as it passes through your body.
First of all, you chew it with your teeth. Then you mix it in your mouth with a liquid called saliva. At the back of the mouth is a leaf-shaped flap of muscle, called the epiglottis. 
As you swallow, this covers your trachea and stops food from entering your lungs.
Digestive System For Kids - How does the Digestive System Work 1

2. After you have swallowed the food, it passes into your stomach, where a strong acid breaks it down.
Digestive System For Kids - How does the Digestive System Work 2

This process is helped by special chemicals called enzymes. There are lots of muscles in the stomach wall that mix the food up with digestive juices. The stomach acid also helps to kill germs in your food.

3. From your stomach, food passes into the small intestine. This is where digestion mostly takes place. Muscles keep the food mixture moving around. The useful food substances pass through the wall of the small intestine and into your bloodstream. Your blood then carries them to where they are needed.
Digestive System For Kids - How does the Digestive System Work 3

Circulatory System For Kids - How does circulatory system work?

Your blood has lots of different jobs to do as it travels around your body. 
It carries the oxygen you have breathed in to every single cell.
It also carries food and other substances that your cells need.
When the cells have done their job, they make waste products which your blood carries away.

What is blood made of ?

Like other parts of your body, your blood is made from cells.
There are two main kinds of blood cells—red and white. 
The red blood cells are the ones that contain a red substance called hemoglobin. It is the hemoglobin in the red blood cells that carries oxygen from the lungs.
The white blood cells kill germs that enter your body. There are fewer white cells than red cells.
A liquid called plasma surrounds the blood cells. 
This is made mostly of water. The plasma carries food to the cells and carries waste products away.

Blood vessels - The tubes that carry blood

Blood travels through tubes called blood vessels. 
The vessels that carry oxygen-rich blood away from your heart are called arteries. 
The vessels that return the blood to your heart are called veins. 
There are thousands of arteries and veins all over your body. They branch into a network of very tiny, tubelike blood vessels called capillaries.
These are very thin so that they can carry blood to all the cells of your body.
Inside your veins are tiny flaps called valves. These open as blood is pushed through after each heartbeat, and they close again to stop the blood from running backwards.

Picking up food

As your blood flows through your body, it picks up food substances, called nutrients, that your cells need. Most of the nutrients enter your bloodstream from an organ below your stomach called the small intestine.
Your blood then carries the nutrients to your liver.
Your liver removes some of the nutrients from the blood and stores them until they are needed.
It also changes some of the nutrients into other substances that your body uses.
After your blood passes through your liver, it continues to carry these nutrients and other substances to all the cells.

Filtering the blood

Your blood is filtered when it passes through your kidneys. 
These lie behind your stomach, near your spine. They filter out some waste products and extra salts from your blood and make urine.
Each kidney passes urine through a tube, called a ureter, to your bladder. 
From the bladder, you excrete urine every day through the urethra.

Respiratory System For Kids - How do we breathe?

How do we breathe?

As you breathe, your chest moves in and out, and up and down.
Inside your chest, there are two flexible, sponge like organs on either side of your heart.

These are your lungs. 

When we inhale (take in air), we breathe in oxygen, a gas which helps to give us energy.
When we exhale (expel air), we breathe out carbon dioxide, a harmful waste gas.
When you breathe in, your lungs fill with air and become larger.
When you breathe out, your lungs become smaller as gas is squeezed out of them.
Respiratory System For Kids - How do we breathe?

Breathing in

You inhale air through your nose and mouth.
Inside your nose are tiny hairs that catch dust from the air.
There is also a sticky liquid called mucus that warms and moistens the incoming air and catches many of the germs you breathe in.
The air you breathe in goes down a pipe called the trachea, also known as your windpipe.
From your windpipe, air enters each lung through two tubes called bronchi. 
Each bronchus divides into smaller and smaller tubes, which eventually lead to tiny, elastic sacs called alveoli. 
There are many millions of alveoli in each lung.
When air enters the alveoli, they blow up like tiny balloons. Then oxygen from the air passes through the walls of the alveoli into capillaries, which are very tiny tubelike vessels through which blood flows.

Breathing out

At the same time as oxygen enters your blood, a waste gas passes from the blood into the alveoli.
The air you exhale contains less oxygen and more carbon dioxide.
This is the waste gas your body produces as oxygen breaks apart the chemicals in your food.
When you breathe in, the alveoli in your lungs blow up like tiny balloons.
Oxygen passes into your capillaries. At the same time, carbon dioxide is passed out.

How do we breathe?

You have muscles in your chest that make you breathe.
Some are fixed to your ribs and make your rib cage move in and out. Below your lungs is a strong, flat sheet of muscle called the diaphragm.
How do we breathe
 As you breathe in, your diaphragm moves downwards and your rib cage moves out, or expands.
This makes a bigger space for the air that enters your lungs.
As you breathe out, your rib cage and diaphragm squeeze your lungs into a smaller space again.
Respiratory System For Kids - How do we breathe

How Many Muscles Are In The Human Body and How do muscles work?

The human body has 639 muscles.

Not all are joined to your bones.

For example, muscles line your blood vessels to keep blood flowing. Your lungs work because of regular muscle movement.
Muscles in the Human Body
Muscles in the Human Body

Some muscles move only when you decide to stand up, sit down, or move in other ways. These are the voluntary muscles that are joined to your bones.
There are other muscles that work without your thinking about them. These involuntary muscles are made of smooth muscle fibers. They mash the food material in your stomach and then act to move it along through your intestines.
Your heart is made of another special kind of muscle called cardiac muscle. It moves in a regular rhythm as it pumps blood to all parts of your body.

How do muscles work?

Muscles are made of tough, elastic tissue.
They are built so that they can contract, which means that they become shorter.
When the muscles whose ends are joined to bones contract, they pull at the bones and make them move.
Muscles are made up of long, thin cells that join together to make muscle fibers.
When the muscle becomes shorter, all the fibers move closer together, making the muscle bulge.
You can see your muscles bulging and relaxing when you move your arms and legs.
If you bend your elbow and clench your fist, the muscles called biceps in your upper arm will bulge.
Muscles can only pull—they can’t push. 
Muscles whose ends are joined to bones work in pairs.
One muscle contracts and pulls the bone one way, and the other contracts to pull the bone back again.

Muscles In The Human Body - How do muscles work?

The human body has 639 muscles.

Not all are joined to your bones.
For example, muscles line your blood vessels to keep blood flowing.
Your lungs work because of regular muscle movement.
Some muscles move only when you decide to stand up, sit down, or move in other ways.
These are the voluntary muscles that are joined to your bones. 
There are other muscles that work without your thinking about them.
These involuntary muscles are made of smooth muscle fibers. They mash the food material in your stomach and then act to move it along through your intestines.
Your heart is made of another special kind of muscle called cardiac muscle. It moves in a regular rhythm as it pumps blood to all parts of your body.
Muscles In The Human Body
Muscles In The Human Body

How do muscles work?

Muscles are made of tough, elastic tissue. They are built so that they can contract, which means that they become shorter.
When the muscles whose ends are joined to bones contract, they pull at the bones and make them move.
Muscles are made up of long, thin cells that join together to make muscle fibers.
When the muscle becomes shorter, all the fibers move closer together, making the muscle bulge. You can see your muscles bulging and relaxing when you move your arms and legs.
If you bend your elbow and clench your fist, the muscles called biceps in your upper arm will bulge.
Muscles can only pull—they can’t push. 
Muscles whose ends are joined to bones work in pairs. One muscle contracts and pulls the bone one way, and the other contracts to pull the bone back again.

Interesting Facts About Muscles

  • Human muscle cells produce enough heat every day to boil almost 2 pints of water for an hour.
  • The tongue is the strongest muscle in the human body. 
  • Muscles make around 40% of human body weight.
  • We utilize more than 200 muscles just to make one step.
  • The foot is responsible for one quarter of all the human body’s muscles
  • Fingers do not have muscles in them, since they are moved by tendons and attached to muscles in the forearm. 
  • When we shiver, our muscles contract involuntarily and this releases energy that keeps the body warm.
  • The heart beats more than 4500 times each hour since the cardiac muscle never gets tired.  While sleeping, playing sport, resting even when going into the toilet, the hearth beats on average 80 beats per minute. 
  • While smiling, we are using about 30 muscles, which control the eyelids, nostrils and brow, working together to show emotions.

Types of joints in the human body - human body for kids

Human body moves in many different ways.
You can bend, stretch, turn, and twist.
You can move because your bones move at your joints, places where your bones meet.
But your bones can’t move by themselves—they need something to pull at them. 
This job is done by your muscles, which are joined to your bones in order to move them.
There are many joints that help your body move.
When you turn your head, bend your knees, or twist your wrists, your joints are in action.
Some joints, such as those in your skull, do not move. These are called fixed joints.
Each of the other kinds of joints does a specific type of movement.

Types of joints in the human body

Types of joints in the human body

Types of joints in the human body

- Ball and socket joints give you the most movement.
The round end of one bone fits into a hollow part of another bone. Examples are your hip joints and shoulder joints.

- Hinge joints work like a door on a hinge.
Movement in hinge joints is only in two directions. Your knees and elbows have hinge joints.

- Pivot joints allow parts of your body to twist.
Your head moves from side to side because it rests on a pivot joint at the top of your spine. In the same way, you can turn your hands over by flipping your wrists.

- Gliding joints are one of the simplest kinds of joints.
They allow a sliding movement when two pieces of bone come together. There are gliding joints on your backbone where the ribs meet the vertebrae.

Bones In The Human Body

Humans have about 200 bones in the body, which are joined together and make up the skeleton. Your skeleton helps give your body its shape. The bones of your skull determine the shape of your head. Long bones hold muscles that shape your arms and legs. Rib bones curve to make the sides of your chest.
Your skeleton is the framework of your body. It holds you up and also helps you to move around.
Some bones protect your main inner organs. For example, your skull protects your brain. And your ribs make a rib cage around your heart and lungs.

What are bones made of?

Bones are hard tissues that are living parts of your body, just as your brain and heart are living parts. Bones contain cells that divide and multiply, causing you to grow. These cells are also always rebuilding the bony tissue to keep it strong. Rebuilding happens less as people grow older. So a broken bone will often heal much more quickly in a child than in an adult.
Bones store substances called minerals, which your body uses. Calcium is a mineral. It helps to make the bones hard.
Bones have a strong covering, called periosteum. Inside, there is a hard layer of compact bone. A long bone, such as the thigh bone, has spongy tissue at its ends, called cancellous bone, and soft marrow in its hollow center.

Some parts of your skeleton, such as your arms and legs, have only a few long bones. Other parts, such as your hands and feet, have many small bones.

How are bones held together?

Your bones are held together by strong, flexible straps called ligaments. The ends of the bones are covered with a smooth, rubbery substance called cartilage. This is the same kind of substance that forms the tip of your nose. Cartilage works like a cushion so that the bones don’t grind against each other. Cartilage is covered in a liquid called synovial fluid. This keeps the bones moving smoothly, like oil in the parts of a machine.

Interesting Facts About Bones

  • Humans have about 300 bones when born. Some of these, fuse together creating a single bone. When maturity is reached, humans have 206 bones in the body.
  • The teeth are not counted as bones.
  • The greatest bone in the body, “the femur”, is around 1/4 of the persons height. 
  • The smallest bone in the body is the stapes (stirrup) located in the middle ear, with size around 1/10 of an inch (2.8 millimetres).
  • The only bone which is full-grown at birth is the stapes bone, and is situated in the ear.
  • Hand, fingers and wrist make the area of the body with most bones - 54.
  • The bones of an adult person make approximately 14 % of the total body weight.
  • The bones are made of approximately 75 % of water
  • Human bones start to grow from birth, until mid 20's. 
  • Broken bones re-grow and repair themselves. 
  • The human skeletal system has six major functions: 1. production of blood cells, 2. support, 3. movement, 4. protection, 5. storage of ions and 6. endocrine regulation.
  • The Bone marrow makes up 4% of a human body mass. 

What are human bones made of?

Bones are hard tissues that are living parts of your body, just as your brain and heart are living parts. Bones contain cells that divide and multiply, causing you to grow.
These cells are also always rebuilding the bony tissue to keep it strong.
Rebuilding happens less as people grow older. So a broken bone will often heal much more quickly in a child than in an adult.
Bones store substances called minerals, which your body uses. Calcium is a mineral. It helps to make the bones hard.
Bones have a strong covering, called periosteum.
Inside, there is a hard layer of compact bone.
A long bone, such as the thigh bone, has spongy tissue at its ends, called cancellous bone, and soft marrow in its hollow center.
Some parts of your skeleton, such as your arms and legs, have only a few long bones. Other parts, such as your hands and feet, have many small bones.

How are bones held together?

Your bones are held together by strong, flexible straps called ligaments.
The ends of the bones are covered with a smooth, rubbery substance called cartilage. This is the same kind of substance that forms the tip of your nose.
Cartilage works like a cushion so that the bones don’t grind against each other. Cartilage is covered in a liquid called synovial fluid.
This keeps the bones moving smoothly, like oil in the parts of a machine.

Human Skeleton For Kids

Humans have about 200 bones in the body, which are joined together and make up the skeleton. 
Your skeleton helps give your body its shape.
The bones of your skull determine the shape of your head.
Long bones hold muscles that shape your arms and legs.
Rib bones curve to make the sides of your chest.
Your skeleton is the framework of your body. It holds you up and also helps you to move around.
Some bones protect your main inner organs. 
For example, your skull protects your brain. And your ribs make a rib cage around your heart and lungs.

What are bones made of?

Bones are hard tissues that are living parts of your body, just as your brain and heart are living parts.
Bones contain cells that divide and multiply, causing you to grow.
These cells are also always rebuilding the bony tissue to keep it strong.
Rebuilding happens less as people grow older. So a broken bone will often heal much more quickly in a child than in an adult.
Bones store substances called minerals, which your body uses. Calcium is a mineral. It helps to make the bones hard.
Bones have a strong covering, called periosteum. Inside, there is a hard layer of compact bone. A long bone, such as the thigh bone, has spongy tissue at its ends, called cancellous bone, and soft marrow in its hollow center.
Some parts of your skeleton, such as your arms and legs, have only a few long bones. Other parts, such as your hands and feet, have many small bones.

How are bones held together?

Your bones are held together by strong, flexible straps called ligaments. 
The ends of the bones are covered with a smooth, rubbery substance called cartilage. 
This is the same kind of substance that forms the tip of your nose.
Cartilage works like a cushion so that the bones don’t grind against each other.
Cartilage is covered in a liquid called synovial fluid.
This keeps the bones moving smoothly, like oil in the parts of a machine.

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Ocean Animals For Kids

Ocean Animals For Kids

Most of the vertebrates that live in the ocean are fish.
Some mammals, reptiles, and birds live there, too.
There is only one group of vertebrates not found in salt water.
These are the amphibians.
Fish have always lived in the sea, of course. There are more than 13,000 different kinds, or species, living in the sea. But the mammals found in the sea are descended from land animals. 
They have to come to the surface to breathe, because they have lungs, not gills.

Fish in the ocean

Fish come in all sorts of different shapes and sizes. 
Some are flat so that they can lie on the seabed without being seen. 
Eels have snakelike bodies.
 Rays, like the skate, are kite-shaped and seem to fly through the water by flapping their huge “wings.”

 Mammals in the ocean

There are three groups of mammals in the sea:

  • whales and dolphins, 
  • seals and sea-lions, and
  •  some rare sea mammals called sirenians, which include the manatee and the dugong.

There are more than 75 different kinds of whales. 
The blue whale is the largest animal that has ever lived. It can grow to be as long as 100 feet (30 meters)! 
Whales need to come up to the surface for air, but sperm whales can hold their breath underwater for over an hour!
Dolphins and porpoises are actually small whales. The killer whale is the largest walrus
dolphin. 
Have you ever seen bottle-nosed dolphins perform in an aquarium? 
They are very intelligent. They communicate with each other by blowing air through their blow-holes to make squeaks, whistles, and clicks.
Seals, sea-lions, and walruses are the only sea mammals that move onto land to give birth to their young. Walruses look like large seals with two long, pointed teeth called tusks.

Reptiles in the ocean

Some turtles and snakes live in the sea. 
Like all reptiles, sea turtles are cold-blooded, so they live only in warm waters. 
The females come out of the sea to lay their eggs in holes on sandy beaches. 
Most sea snakes never leave the sea. 
They swim by waving their flattened bodies from side to side and by using their oarlike tails as a paddle.

 Birds in the ocean

Penguins spend much of their lives in the sea, often hunting fish, their main food. 
Instead of wings, penguins have flippers which help them to swim. 
Penguins come to the surface of the water to breathe. 
They move onto land to lay their eggs and raise their young.

Predator Prey Relationship - Examples

The world is a dangerous place for most animals.
Many need to defend themselves against other animals that want to eat them.

Definition of prey

An animal that is hunted, killed, and eaten by another is called prey. 

Definition of predator

Animals that hunt prey are called predators.

Predator prey relationship examples

Some animals are able to disguise, or camouflage, themselves as a protection against predators.
But there are many other ways in which an animal can defend itself.
One species of lizard, the leaf-tailed gecko of Australia, has a tail that looks like its head!
You can imagine how confusing this must be for the lizard’s enemies. If a predator grabs this gecko by the tail, the tail breaks off, and the gecko can escape. Later, a new tail will grow.
Birds that nest on the ground are usually camouflaged.
Goatsuckers (also known as nightjars) and whippoorwills look like a pile of dead leaves. Ringed plovers look like the pebbles on the beaches where they nest.
Goatsucker
A certain group of lizards, called chameleons, can change the shading of their skin color to match their surroundings and confuse their enemies. 
For example, green chameleons can change from light green to dark green.
Green chameleon
Camouflage can help some predators to get near their prey without being seen. The tiger’s stripes help it to blend in with the tall grasses of its hunting ground.
Polar bears have white fur to match the snow.

Some animals, including opossums and snakes, pretend to be dead when they are in danger. 

Most predators prefer live prey, so they leave the “dead” animal alone.

Other snakes defend themselves with poisonous bites.

Armadillos and pangolins are two species of animals that roll up into a ball when in danger. 

This protects the soft undersides of their bodies. Both animals have a thick coat of armor made of bony plates on the outside of their bodies.
When predators come close, porcupines and hedgehogs might also defend themselves by rolling up into a ball. Such a ball of needle-sharp quills scares away many predators.
Porcupines have a painful and effective way of dealing with predators. They have spines called quills, that drop out easily.
When a porcupine is threatened, it may run backward toward its enemy. Quills get stuck in the predator’s nose and face or other part of the body, giving the porcupine a chance to run away.

The skin of animals that are poisonous to eat is often brightly colored. 

The bright colors of the arrow-poison frogs of South America warn predators to keep away! 
Some salamanders ooze poisons from their skin when they are in danger.
When the prickly puffer fish is frightened, it can blow itself up to twice its normal size.
Most predators don't want to eat a prickly balloon. Its flesh is usually poisonous, too!
When do Bears Hibernate? - hibernation for kids

When do Bears Hibernate? - hibernation for kids

Generally bears enter hibernation in early October and emerge sometime in April or May.

Hibernating animals breathe much more slowly and their body temperature falls.
They also need much less food. 

They build up a thick layer of fat during the warmer months and use it up very slowly during hibernation.
For animals big as the bear it is extremely difficult to find enough food during the winter, and therefore they go into hibernation.
Yet in order to survive this long period of hibernation, the bears must previously build up their body weight by accumulating fat. 
Hibernation cycle is just another unique natural adaptation which allows the animals like the bear to survive during the severe winter time.

Do Raccoon's Hibernate in Winter? - hibernation for kids

What Is Hibernation?

In those parts of the world where some months of the year are very cold, mice and other small mammals hibernate.
This means that they go into an inactive, sleeplike state for the cold period and only fully wake up when the weather turns warm again.
Hibernating animals breathe much more slowly and their body temperature falls. 
They also need much less food. 
They build up a thick layer of fat during the warmer months and use it up very slowly during hibernation.
A dormouse can sleep in its nest for up to nine months in a year. It may wake up at intervals during this time to nibble at its store of nuts and berries.

Do Raccoon's Hibernate in Winter?

We might say that the raccoon's do not truly hibernate during the cold winter days, but they rather "hole up" for days, weeks, or even months, depending on the weather.
Raccoon hibernation is more like torpor, meaning their heartbeat, temperature, and body activities slow down, and they are only a little alert.
Raccoon's wake up from time to time during winter and sometimes even go out to hunt, they eat and go back to sleep.
During sleep their heartbeats and breathing slow down, but not as much as hibernator bodies do.

What is a Backbone and What does the Backbone do?

Vertebrate animals have a spine, or backbone, and a cranium (brain case). 
The spine is a long column of bones called vertebrae that run all the way along an animal’s back.
Most vertebrates have vertebrae made of bones.
Some, like sharks, have vertebrae of cartilage.
What is a Backbone and What does the Backbone do

We can feel our vertebrae by running our hand down the back of our neck and between our shoulder blades.
Can you feel a row of hard, bony lumps?
They run all the way down to your bottom.
Every animal in the six classes of vertebrates - bony fish, cartilaginous fish, amphibians, reptiles, birds and mammals - has a spine or backbone.
What is a Backbone and What does the Backbone do?


What does the backbone do?

The backbone has a very important job to do.
Every vertebra that makes up the backbone has a hole in the middle, and is joined to the next by a rubbery pad of cartilage.
The backbone is like a flexible, hollow tube. Through the middle of this tube runs the spinal cord.
The spinal cord is a thick bundle of nerves that carries messages from a vertebrate’s brain to the rest of its body.
The spinal cord also carries information back from the body to the brain. The backbone protects this vital passageway of nerves.

Every animal in the six classes of vertebrates:
  • bony fish, 
  • cartilaginous fish, 
  • amphibians, 
  • reptiles, 
  • birds, and 
  • mammals
has a spine, or backbone.
Messages travel rapidly along the nerves between your foot, spinal cord, and brain.
When the water is too hot, you quickly lift up your leg.
Your brain then receives a signal that the foot is now out of the water.
If you dip your foot into hot water, messages will race through your spinal cord and to your brain to say that the water is too hot and that it’s causing you pain.
Messages will then race back to your leg muscles to take your foot out of the water.
Reacting to pain

Imagine how busy the nerves in your backbone are! 
Thousands of messages rush along them every second.
If the spinal cord gets damaged, these messages can’t get through. Sometimes, people who have injured their back can’t move certain parts of their body.

Treasure map for kids - Art projects for kids

1. You need:


2. Draw a map of an imaginary island.
Treasure map for kids - Art projects for kids 2

3. Draw and invent names for these things on your map:
Treasure map for kids - Art projects for kids 3

4. Draw some dangers on the map:
Treasure map for kids - Art projects for kids 4

5. You are Alabama Smith or Vicky Vermont. How did you find the treasure? Draw your route on the map in black pen.
Treasure map for kids - Art projects for kids 5

6. Write your story.
Treasure map for kids - Art projects for kids 6

7.Show your map to the class. Tell your adventure story.
Treasure map for kids - Art projects for kids 7

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Marco Polo facts for kids

Who was Marco Polo?

Marco Polo was the first European to travel to Asia and tell his story. His book, "The Travels of Marco Polo" is the most famous travel book in history.
Marco Polo was born in 1254 in Venice.
When he was 17 he traveled with his father and uncle to China.
Their trip took three years.
The Emperor Kublai Khan was surprised to hear that there were Europeans in China.
He invited them to his palace and he gave Marco a job.

Marco worked for the Emperor for many years.
He traveled all over China and he made many amazing discoveries. In Europe people didn't have many things that he saw. People put black stones not wood on their fires.
These black stones - or coal’ -came from under the ground.

Chinese food was different from Italian food.
Some of it was very strange but Marco Polo really loved two foods in China. One was ice cream and the other was spaghetti.

He saw people with small glass circles in front of their eyes. These ‘glasses’ helped people to see better. What a good idea! In Europe the money was gold and silver coins.

In China people used paper money. It was much easier to use.


In 1292 the Polos decided to go back to Italy.
Marco took with him many of his Chinese discoveries.
The Polos arrived back in Venice in 1295.
Marco was 41 and his father and uncle were old men. Their friends didn't recognize them.

Marco told fantastic stories about China and his discoveries.
No one believed him. 
They called him ‘the man of a million lies.’
Marco decided to give a big party. The guests ate spaghetti and ice cream.
The Polos were wearing their old travelling clothes.
Marco took a knife. He cut his clothes.
Gold and jewels from China fell onto the floor.
After this, people in Venice believed Marco’s stories.

In 1298 Marco went to prison. 
In prison he told stories of his journey and his discoveries to a friend.
The friend wrote them down.
One day a man called Christopher Columbus read Marco Polo’s book.
He decided to sail west to China.
He didn't find China ... but that’s another story!

Art projects for kids - My Star File

1. You need:

2. Choose a star. Glue some photos onto the sheet of paper. Cut out or write their name.

3. Fold the sheet of paper twice to make a booklet with the photos on the inside.

4. On the front page write some star facts.

5. On the middle pages write some song titles.

6. On the back page write about your star’s looks and likes.

7. Work with a partner. Talk about your star. Guess who it is.

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