Where beetles live

Beetles are found all over the world except in Antarctica. Most of the species live on the land. However, some, like the whirligig, water scavenger, and true water beetle, have adapted to live in the water.

Physical features

Like other insects, beetles have three major body segments: the head, thorax, and abdomen. A beetle's head has one pair of antennae and a pair of compound eyes. The thorax has two pairs of wings and three pairs of legs. The abdomen of a beetle has the reproductive organs.

Beetles have antennae, or feelers, to help them find food and recognize other beetles. The body is covered with a hard layer called cuticle that supports the internal organs and protects the body. Beetles have chewing jaws called mandibles.

Beetles are colorful insects ranging from brilliant orange, red, or yellow to iridescent green or blue with a metallic sheen. Some are plain black or have brownish patterns that camouflage them on wood or soil.

Beetles vary in size. Some are only about ¹/₁₀₀ inch (0.025 centimeter) long, whereas tropical rhinoceros beetles and goliath beetles may reach lengths of 4 to 6 inches (10 to 15 centimeters). At one time, all beetles were flying insects, but many, like the common ground beetle, have given up flying and move about on their six legs.

Behavior

There are two kinds of beetles, the helpful and the harmful. The helpful kind are valuable because they prey on insect pests and useless garbage that collects in houses, hedges, tree stumps, birds' nests, and similar places. The harmful kinds are those, both adults and larvae, who destroy crops and timber and spread diseases.

Beetles stridulate, or make a high-pitched sound, by rubbing one part of the body against another. This is done by scraping the legs over very fine ridges on another part of the body. When frightened, some of them eject an unpleasant-smelling liquid from the end of their body.

Life cycle

Many beetles produce light and sound to either attract a mate or frighten an enemy. A male beetle, such as a firefly, flashes its light to say that it is ready to mate, and a female returns the signal.

The females lay fertilized eggs. When active larvae called grubs hatch from the eggs, they spend all their time eating. Most grubs eat leaves, flowers, stems, roots, and even the wood of trees. They shed their skin as they grow until they become pupae, when they are soft, pale and inactive. After this stage they emerge as fully grown beetles. The life span of a beetle ranges from a few months in some species to more than four years in others.