Insects

There are more types of insects than all other types of animals put together. Scientists know about a million types or species, but there may be many more. Insects belong to a group of animals known as arthropods. They are also invertebrates because they have no bones inside their bodies. They have a hard outer shell for protection. It is called an exoskeleton.

All insects have three body parts: a head, thorax and abdomen. On the head are the antennae, mouth and compound eyes. A compound eye holds many tiny 'eyes.' The thorax is the part of the insect just behind the head. Most insects have wings. The insect's wings and legs are attached to the thorax. Insects have 3 pairs of jointed legs. The abdomen holds the insect's heart, digestive system and reproductive parts. Most insects have two pairs of wings, but some have none. A fly has only one pair.

Insects live all over the world. They live in many kinds of areas. Some live in warm, damp areas. Some live in trees, underground, or in fresh water. Stag beetles live in trees. Slow-moving or still water is a good place to locate insects. Whirligig beetles live on the surface of the water. They feed on mosquito larvae or dead insects. Wingless moths can survive in the cold of Antarctica. Grasshoppers live in fields where they can find plenty of food.

An adult insect may live a very short life. During that time, it must find a mate and produce offspring. Male insects use different ways to attract females. Deathwatch beetles tap their head against wood to attract a mate. Sometimes insects use different ways of flying or scents to be noticed. When a praying mantis mates, she sometimes eats the male. He helps to nourish the eggs which the female will lay. Stag beetles use their huge jaws to fight off other males who want the female.

Insects lay their eggs in different places. Usually it is a place which can provide food and be safe for the offspring. Inside a hive the queen lays her eggs inside waxy cells. Spider-hunting wasps lay their eggs in underground burrows. Leaf miner flies lay their eggs inside or underneath leaves.

An insect's diet depends on where it lives. Some feed on plants. Others eat blood or each other. There are two main methods of feeding: sucking, or biting and chewing. It depends on the type of mouth and jaws the insect has. Butterflies and moths suck up liquid nectar with a long, hollow tube. Tiger beetles have powerful jaws to bite and chew their food.

Insects have different ways of moving to find food and escape from predators. Some don't move much at all. Some move a lot. Many have special adaptations to help them move, such as long legs or wings. Insect wings come in a variety of shapes and types. They are made strong by many hollow tubes called veins. Water striders can walk over water. Pads on their legs are coated with wax which repels water and keeps them from sinking. Houseflies have hairy, sticky pads on their feet to keep them from falling from ceilings.

In summary, scientists know only about a million different kinds of insects, but there may be many more. Insects make up a larger number of types than all other animals together. Insects belong to the species known as arthropods. They are invertebrates and have no internal skeleton. Their bodies are covered and protected by a hard shell called an exoskeleton.