The Body of an Insect is a Masterpiece


The body of an insect is a masterpiece of design. In many ways, insect bodies are much more efficient than our own. The basic design is quite simple. The bodies of all insects are divided into three sections, as shown at right. The sections common to all insects are the head, the thorax, and the abdomen.

The head has two eyes, two antennae, and a mouth. Insects eat a wide variety of food. To do this, they have a wide variety of mouth shapes. But there are really only four basic kinds of mouths. Some insects have mouths that soak up liquids like sponges. Others have mouths that are made for sucking. Many have mouths that pierce like hypodermic needles. And a large number of them use their mouths for crushing and chewing.

All the basic parts of an insect are easy to see on a grasshopper.

This fly has long mouth parts that end in a broad tip. The tip is porous, and the fly uses it like a sponge to soak up water and other liquids. Can you find the fly’s sponging mouth parts?

Flies belong to a group of insects called diptera, which means “two wings.” But don’t let the name fool you. They really have four wings like other insects. However, the back two are just tiny stubs that are usually hidden beneath the front wings. See if you can find the back two “wings” on this fly.

Mosquitoes and many other insects have mouth parts that work like hypodermic needles. They pierce the skin or the surface of a leaf, and then suck out the liquid inside.

Many insects have mouths that work like ours—they bite and chew. But insects don’t have teeth. So they need jaws that are strong and have sharp edges to cut and chew their food. Tiger beetles move their jaws sideways to chew their food, not up and down.

Moths and butterflies have long mouth parts that look like hoses. They use them to suck nectar from flowers, just like you would sip a milkshake through a straw. Do you see this butterfly’s mouth parts sucking nectar from the center of the flower?

When moths and butterflies aren’t using their mouth parts, they can roll them up like a hose! The mouths of some moths are actually twice as long as the rest of their bodies.

Your skeleton is on the inside of your body. But insects have theirs on the outside. This kind of skeleton is called an exoskeleton. It supports the muscles inside the insect’s body, and it gives the little insect a “coat of armor” for protection.