What is an Insect?
An insect is quite different from you and me. It has a body that is divided into three parts: the head, the middle which is called the thorax and the abdomen which is usually the largest part of the body.
Did you know that many insects can see in more than one direction without turning their heads? This is because they have compound eyes. Compound eyes are made up of lots of cone-shaped units packed close together.
An insect has something else which we don’t. It has two antennae sticking out from the top of its head. Insects use their antennae to tell them about sound, touch, taste and smell.
Now we almost have the complete insect; a body divided into three parts, compound eyes and two antennae. But we’ve left out something… the legs. Guess how many legs the insect has? Well, multiply two by three and you have the answer.
The insect has six legs. Add two pairs of wings to the insects that fly and you have the complete picture.
This is true of most but not all insects.
Have you ever wondered how an insect walks? If I had six legs I’d probably get them all tangled up! Well most insects move three legs at a time. This means that they rest three legs on the ground, while they lift the other three. But which three do they move to keep their balance? They move the first and last of one side, plus the middle leg of the other side. Have you got that?
Stranger still is the insect walking upside down on the ceiling. Don’t worry, it won’t fall on you. This is because the legs are tipped with claws by which the insect is able to hold onto any surface. What’s more under its claws it has a sticky pad which allows it to cling to any surface and even walk upside down on the ceiling.
Last, but not least, did you know that insects taste partly through their mouths and sometimes also through their feet!
Ears or No Ears
I hope you’re all ears for what comes next, because it may surprise you to hear that only a few insects have ‘ears’. Among the insects that have hearing organs are the grasshoppers, crickets, katydids, cicadas and some moths. The short-horned grasshoppers, often called locusts have their hearing organs located on the side of their abdomens.
The long-horned grasshoppers, katydids and crickets have their ears on their front legs.
How do other insects hear? Most insects have some hair on their bodies and when these vibrate, they know that something is approaching. They also use their antennae to tell them about sound.
Talking about sound, you must have heard the cheerful chirping of the grasshopper or the shrill song of the cricket. Neither of them sing like you and I do because they don’t have voices.
They are clever musicians or fiddlers. Grasshoppers make music by drawing their hind legs like a bow against the edge of their wings, and the brown cricket, lying low on the ground, sings its song, by rubbing its two front wings together.
If you locate this talented musician, you will find that it is a male. It sings to call the female. Because crickets have ears, the female actually responds to the song.
First published by National Book Trust, India