General Knowledge · Class 10 · Nature and animals
Why animals behave as they do
A sea turtle hatches at night on a beach, alone, and heads straight for the sea. Nobody taught it. How does it know?
Small test at the end: scroll down to the end of this page for five short questions that check what you have learnt. Tap an answer, then press Check answer. Go to the questions ↓
Jump to: Read first · Try it away from the screen · Check it yourself · Check yourself · For teachers
Read first
6 facts. The questions below make you use them, not just remember them.
- Some behaviour is instinct: animals are born able to do it, like a spider spinning its first web or a hatchling turtle heading for the bright sea horizon. Other behaviour is learned, like crows learning which houses throw out food.
- Every year Amur falcons fly from eastern Asia through Nagaland to southern Africa and back, a round trip of about 22,000 km. Villages in Nagaland that once hunted them now protect them.
- Ants leave a chemical trail as they walk. Others follow the smell, which is why ants march in a line to food.
- Elephants talk with very low rumbles, too low for us to hear, which can travel several kilometres.
- The plain tiger butterfly tastes bad to birds. The harmless female Danaid eggfly looks almost the same, so birds avoid it too. This copying is called mimicry.
- Salim Ali, the "Birdman of India", showed how much can be learned about animals just by watching carefully and writing everything down.
Offline
Try it away from the screen
Put a few grains of sugar on the floor near an ant line and watch for 15 minutes. Draw the path the ants take before and after they find it. Then wipe the path with a wet cloth and see what happens.
Make it on paper. Keep it with you. Nothing to upload.
Check it yourself
Animal videos often claim an animal "knows" or "feels" something. Ask: what did the animal actually do, and could there be a simpler reason? Scientists test one explanation at a time.
Check yourself
Five questions about what this page teaches. Choose an answer and press Check answer, or open "See the answer and why". Nothing is saved or sent: your choices stay on this screen and disappear when you leave or reload the page.
How do you want to answer? You choose, and you can change at any time.
See the answer and why
- A. A young elephant finding water by following its mother Not this one. That is learned by following older elephants.
- B. A hatchling turtle heading for the sea Correct. Yes. It does this the first time, with no one to teach it.
- C. A crow learning which homes throw out food scraps every morning Not this one. That comes from experience, so it is learned.
- D. A dog sitting when told "sit" Not this one. That is learned through training.
See the answer and why
- A. A leader ant shouts directions to every ant behind it Not this one. Ants do not shout. They use smell.
- B. They can see the food from far away Not this one. Most ants have poor eyesight. Smell guides them.
- C. They follow a scent trail left by other ants Correct. Yes. Wiping the trail away confuses them for a while.
- D. They are walking along cracks in the floor Not this one. They follow a scent trail, even across smooth floors.
See the answer and why
- A. Birds avoid it, thinking it tastes bad Correct. Yes. Looking like a bad-tasting butterfly protects it.
- B. It eats the same plant, so it changes colour Not this one. Mimicry evolved over many generations; it is not caused by food.
- C. They are the same kind of butterfly Not this one. They are different kinds of butterfly.
- D. It wants to make friends with the plain tiger Not this one. Mimicry protects it from predators. It is not about friendship.
See the answer and why
- A. 6,460 Not this one. That takes away instead of dividing.
- B. 200 Not this one. Check: 200 × 340 is 68,000, ten times too far.
- C. 20 Correct. Yes. 6,800 ÷ 340 = 20 seconds.
- D. 2 Not this one. Check: 2 × 340 is only 680 m.
See the answer and why
- A. The falcons stopped coming to Nagaland and now fly a different way Not this one. They still come in huge numbers each autumn.
- B. They were all moved to zoos Not this one. They are wild birds, protected where they roost.
- C. Villages that once hunted them now protect them Correct. Yes. Since about 2013 local communities have guarded the roosts.
- D. The falcons learned to hide Not this one. People changed, not the falcons.
For teachers and grown-upsWhere the facts come from, and how to use this round.
Sources and notes
- Amur falcon conservation in Doyang, Wokha district, Nagaland, from 2013; satellite tracking by the Wildlife Institute of India.
- Elephant infrasound: rumbles below about 20 Hz. Safety: no insecticide in the ant task.