Category Science

What is the difference between a moth and a butterfly?

Butterflies are often brightly coloured. They fly during the day and their antennae have rounded ends. Moths have feathery antennae, and fly at night.

Which butterfly can fly thousands of kilometres?

The American monarch butterfly lives in the United States and Canada. When autumn approaches, thousands travel south to Florida, California and Mexico – a journey of over 3,000 kilometres.

Is it true? Butterflies and moths have scales.

Yes. Butterflies and moths have four wings covered with tiny overlapping scales which shimmer in the light. These scales give them their bold patterns and beautiful colours.

Amazing! Before laying eggs, butterflies test food plants with their antennae and tongues to check that the leaves are suitable for their caterpillars. But some also stamp on the leaves, because butterflies, flies and honeybees have taste organs in their feet!

How do caterpillars become butterflies?

When a caterpillar is fully grown, it turns into a pupa. Inside the pupa case the caterpillar’s body breaks down and gradually becomes a butterfly. This change is called metamorphosis.

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Are spiders insects?

No. Spiders belong to a group called arachnids, which also includes scorpions, mites and ticks. Spiders all have eight legs, one pair more than insects. They have two body parts – a head and an abdomen – and most have eight simple eyes.

Is it true? Spiders and insects have bones.

No. Instead they all have a hard casing on the outside called an exoskeleton. This protects their soft insides like a suit of armour and gives them their shape. They have to replace this casing with a new one in order to grow.

Amazing! There are creepy-crawlies living just about everywhere in the world, under water, in caves, down deep holes and even on the tops of mountains. Most of the animals in the world are insects. They make up 85% of all known animal species and there are probably millions more waiting to be discovered!

What makes an insect an insect?

Although they may look different from one another, every adult insect has six legs and three parts to its body. The head is at the front, the thorax in the middle and the abdomen at the back. Many insects have wings for flying and long feelers or antennae.

What is a minibeast?

Creepy-crawlies can also be called minibeasts. You will find other kinds of minibeasts, which are related to spiders and insects, such as woodlice, slugs, snails, worms, centipedes and millipedes.

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Why do spiders spin webs?

Sticky webs can be a home and a trap to catch flying insects. But not all spiders make webs, and not all webs are the same. The ogre-eyed spider makes a web like a net. It hangs down holding the web, waiting to throw it over its prey.

Do spiders have teeth?

No, but they have fangs for stabbing prey and injecting it with poison and special juices. The victims turn to liquid inside so that the spider can then suck them up like soup!

Amazing! The water spider makes its home under the surface of the water. It spins a web like a balloon which it fills with air bubbles. It waits inside until it spots its prey, and then darts out to seize it.

Is it true? Some spiders eat their webs.

Yes. Orb web spiders eat the old web before they spin a new one. A web may take an hour to spin. The silk is as strong as steel of the same thickness.

What can see with its tail?

As well as a sting, some scorpions also have light-sensitive cells in their tails. These cells let them know whether it’s day or night, even when their heads are underground. Scorpions hunt at night and spend the day hidden in their burrows.

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A caterpillar or worm? Can you tell the difference?

It’s easy to think caterpillars and worms are the same. After all, they’re both usually slow-moving, and long and squiggly with the caterpillars even have the word worm in their name, adding to the confusion. But while they have a few similarities, caterpillars and worms are basically different creatures.

Similarities

Both caterpillars and worms can be pests or friends of humans and the environment. For instance, both can destroy plants (earthworms can eat the roots of a healthy plant, and caterpillars can polish off large quantities of leaves) but they are also food for larger creatures. While worms help with composting, butterflies and moths emerging from caterpillars help in the pollination of plants, many of which produce food for several creatures and humans.

The difference

Caterpillars are the larvae of butterflies or moths. Essentially, they are just a stage in the life cycle of an insect. Worms, on the other hand, are not a phase; they are tubular invertebrates. One of the most notable differences between the two is that worms do not have legs; caterpillars usually have three pairs of legs. Worms also normally do not have eyes. Instead, they have what are called receptors that help them sense if there’s light or darkness. Also, while worms seem to prefer areas that are dark and moist, caterpillars do not appear to be picky in that department.

Here’s a trivia coming your way. The fall armyworm, which has been getting a lot of attention for its large-scale destruction of crops in India, is not a worm at all. It is actually the larva of the fall armyworm moth!

 

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Why are helicopters used for rescuing people?

Helicopters make good rescue aircraft because they can hover in the air and land in small spaces. At sea they hover while the crew pulls people from the water. They are also used to lift injured mountaineers to hospital.

Who invented the first true helicopter?

People had been making brief helicopter flights since 1907, but the first successful helicopter flight was in 1939. Inventor Igor, Sikorsky flew his VS-300, which had a single main rotor and a tail rotor. This was the ancestor of all modern helicopters.

Amazing! Helicopters can be used as cranes! ‘Skycranes’ can move heavy objects over short distances. They have a cargo space where the fuselage normally is.

Is it true? All helicopters have two rotors.

No. Very modern helicopters have a tail thruster, instead of a second rotor, but most helicopters do have two rotors. As the engine spins the main rotor one way, it also tries to spin the fuselage the other way. A second rotor on the tail stops this happening. On twin-rotor helicopters, the main rotors spin in opposite directions, so no tail rotor is needed.

What is an autogyro?

An autogyro has a rotor that is not driven by an engine. As the autogyro is pushed along by its propeller, the rotor spins round automatically, providing the lift that keeps the autogyro in the air.

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Which jet plane can hover?

The Harrier attack aircraft can take off and land vertically and also hover in the air. The exhaust from its jet engines comes out of four swivelling nozzles. For hovering, the nozzles point downwards. For forward flight, they point backwards.

Amazing! Engineers built a bizarre machine nicknamed the ‘Flying Bedstead’ to test vertical take-off and landing aircraft. It had two jet engines, and its real name was the Thrust Measuring Rig.

Which planes can take off and land in cities?

The de Havilland Dash flies between small airports with short runways that are often near city centres. The Dash can take off and land on a runway only a few hundred metres long.

Is it true? People can fly with jet-packs.

Yes. By strapping on the Bell rocket belt, a pilot could take off and hover in the air. At the beginning of the film Thunderball, James Bond escapes from his enemies with one. However the amount of fuel stored in the rocket belt limits the flying time to less than 30 seconds.

Which plane can swivel its engines?

The Bell/Boeing V-22 Osprey is part helicopter, part aeroplane. It has propellers or proprotors, which swivel upright for take-off, and it works like a helicopter. To go forwards, they swivel down and it flies like a plane.

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