Definition:

An insect is a arthropod which includes spiders, scorpions, crustaceans etc. However, not all arthropods are insects.

Body Structure:

Insects have a specific body structure. An insect’s main body is made of three parts: the head, thorax and abdomen. They also have three legs and one pair of antenna. Spiders have eight legs and only two body parts. Crustaceans can have more than one pair of antenna.

Senses:

Insects that have eyes usually will have compound eyes. These eyes are made of multiple tiny lenses. Usually, they will have lots of lenses. A dragonfly has 28000 lenses.

Some insects rely on smell. Ants for example. They use their antenna to smell. Since ants are blind, their senses of smell is extremely good. If an ant did not have antenna, it wouldn’t live.

Hearing is also important to some other insects. Mosquitoes use it for example. Their antenna can sense sound sources with pinpoint accuracy. Mosquitoes use this ability to target animals and people.

When an insect looks for food, it often locates it by smell or sight. When it finds food, it will usually taste it first. Insects can taste salty, sour, sweet and bitter. Most insects taste with the mouth, however, ants, bees, and wasps use antenna; flies and butterflies use feet.

Insects use a wide amount of varieties of propulsion: legs, wings, jet propulsion, you name it. Most flying insects have two pairs of wings, aside from flies.

Sometimes, they are separate like a dragonfly. Most of the time, however, they are joined into one piece by microscopic hooks.

There are two kinds of flying: direct flight and indirect flight.

In direct flight, the muscles are directly attached to the wings for more agile flying.

In indirect flight, the muscles are attached to the thorax, so that when the thorax goes down, the wings go up. In the same way, when the thorax goes up, the wings go down.

Insects breath through small openings in the sides which let air flow through and circulate throughout the body. The openings are called spiracles.

Insects can be harmful or helpful. They can pollinate, get rid of carrion, produce sil and honey. Dragonflies also each about 100 mosquitoes a day.