Super Senses

Has this ever happened to you?

You were eating in the playground, an eagle flew down and took away your roti.

You dropped something sweet on the ground and within minutes many ants collected around it.

As you walked softly past a sleeping dog, its ears shot up at once.

Why does it happen? Think and tell

Animals also have different senses. They can see, hear, taste, smell and feel. Some animals can see their prey from far away. Some can hear even the faintest sound. Some animals can find their friends by their smell. The animal world is full of examples of amazing senses.

How did the ant recognise a friend?

An ant was going along on the ground. It saw a group of ants coming from the other side. The first ant quickly came back to its hole. The ant guarding the hole recognised it and let it in.

 Think and Tell

- How did the ant know that the other ants were not from its group?

- How did the guard ant recognise this ant?

Many years ago a scientist did many experiments like this.

He found out that as the ants move, they leave a smell on the ground. The other ants follow the smell to find the way.

Now can you guess why the ants behaved like that when you blocked their path?

Some male insects can recognise their females by their smell.

- Have you ever been troubled by mosquitoes? Just think, how do they know where you are?

  Mosquitoes can find you by the smell of your body. They also find you by the smell of the sole of your feet and the heat of your body.

- Have you seen a dog sniffing here and there? What do you think it is trying to smell?

    Dogs mark out their own area on the road. They can make out if another dog has come into their area by the smell of its urine or potty             (latrine).

 Discuss

- Do the clothes of any of your family members smell? whose?

- Did you ever come across any smell in a crowded place such as a fair, bus, train etc.

Why so?

Today Rajni had to go out for some important work. She had to leave her six- month old son Deepak with her sister Sushila. Sushila also has a baby of the same age. It was funny that both the babies did potty at the same time. She happily cleaned her daughter but when she was cleaning her sister’s son Deepak, she covered her nose with her dupatta (scarf).

 Think and discuss

- Sushila covered her nose when she cleaned Deepak’s nappy, but not when she cleaned her daughter. Why do you think she did this?

- How do you feel when you walk near a heap of garbage? Think of the children who spend the whole day picking things from such garbage.

- Is a smell ‘good’ or ‘bad’ for everyone in the same way? Or does it depend on how each one feels about it?

Let’s see

- Write the name of a bird which has eyes in front of its head (like in humans).

- Write the names of some birds which have eyes on either side of the head. What is the size of their eyes as compared to the size of their          head?

  Most of the birds have their eyes on either side of the head. Their eyes can focus on two different things at a time. When they look straight          ahead, both their eyes focus on the same object.

   You must have seen birds moving their neck very often. Do you know why? In most of the birds, eyes are fixed and cannot move. So birds have to turn their heads to see around.

Looking with one or both eyes

Close your right eye or cover it with your hand. Tell your friend to stand to your right, at some distance, and ask him to do some action (wave hand, shake head, etc.)

- Could you see your friend’s action, without moving your neck?

- Now try to look at your friend’s action with both your eyes open but without moving your neck.

- What was the difference on looking with one or both eyes?

- Now toss a small ball or a coin and try to catch it. Try this with both your eyes open. Then close one eye and try to catch it. When was it easier to catch?

- Imagine how it would be to have your eyes in place of your ears? What would you be able to do then, which you cannot do now?

Some birds like kites, eagles, vultures can see four times as far as we can. These birds can see things from a distance of eight metres what we can see from a distance of two metres.

- Now can you guess from what distance can an eagle in the sky can see a roti on the ground?

Do animals see colours?

Animals cannot see as many colours as we can. See how things in these pictures will be seen by some animals.

It is believed that animals that are awake in the daytime can see some colours. Those animals that are awake at night can see things only in black and white colours.

Sharp ear

In Class IV, you read that we cannot easily see birds’ ears. Their ears are small holes covered with feathers.

 Think

Is there some link between the size of animals’ ears and their hearing?

 Try this

For this activity find a quiet place in your school. Tell one of your friends to stand at a short distance and ask him to say something softly. The rest of you should listen carefully. Then all of you put your hands behind your ears, as shown in the picture. Let the same child say something again as softly as before. In which case was the sound sharper? Ask your friends too.

- Put your hands over your ears and say something. Can you hear your own voice?

- Sit near a desk. Tap the desk once with your hand. Listen carefully. Now put your ear on the desk as shown in the picture. Tap on the desk once again with your hand. Listen again. Was there any difference in the sound of the tap?

This is how snakes hear. They do not have external ears (which you can see). They only feel the vibrations on the ground.

Sounds send messages

- High up on a tree, a langur warns others of dangers like a tiger or leopard. The langur does this by making a special warning call.

- Birds also give alarm calls to warn about the danger. Some birds even have different sounds for different kinds of dangers. For example, there is a different warning call if the enemy is coming from the sky or if the enemy is on the ground.

- Fishes give alarm call by electric signals.

        Some animals start behaving in a different way when an earthquake or storm is about to come. People who live in forests and can observe such behaviour of animals come to know of the danger.

           Dolphins also make different sounds to give messages to each other. Scientists believe that many animals have a special language of their own.

Say it with sounds

Just like birds and dolphins you can also make your own language of sounds for giving messages. Remember you have to talk to your friends with only sounds and no words. How and when will you need to give an alarm call? For example, when the teacher is coming to the classroom!

Sleeping-waking

Some animals go into a long, deep sleep in certain seasons. Then they are not seen for many months.

- Have you noticed that during the cold season you cannot see any lizard in the house? Where do you think they have gone?

How will you show the clock for a house-lizard in winters?

The tiger is one of the most alert animals. And yet, today tigers are in danger.

- What do you think are some of the dangers to tigers in the jungle?

- Can human beings also be a threat to animals? How?

Do you know that today many animals are killed and their parts are sold? Elephants are killed for their tusks, rhinoceros for its horn, tigers, crocodiles and snakes for their skins. Musk deer are killed just to make a little scent from its musk. People who kill animals are called hunters and poachers.