Insect

Insect refers to animals with three main body parts: head, thorax, and abdomen. Every insect has six legs attached to the thorax, antennae for sensing, and compound eyes that detect motion from many angles. Many also have wings, making them the only invertebrates capable of powered flight.

Insects wear exoskeletons made of chitin, a tough yet flexible material that protects organs and reduces water loss. Because exoskeletons do not stretch, insects molt several times as they grow. Between molts, hormones guide development and prepare the body for changing life stages.

Life cycles vary. Some insects undergo gradual metamorphosis, hatching as nymphs that resemble small adults, like grasshoppers. Others experience complete metamorphosis with four stages: egg, larva, pupa, and adult. Butterflies, beetles, and flies spend larval stages eating and storing energy, then transform inside cocoons before emerging as winged adults ready to disperse and reproduce.

Insects occupy almost every habitat. Bees and butterflies pollinate flowers, ants aerate soil, termites recycle wood, and dragonflies patrol wetlands for mosquitoes. Some species live alone, while others form complex societies such as honeybee hives or leafcutter ant colonies where individuals take on specialized roles.

Humans rely on insects more than they realize. One in every three bites of food depends on insect pollination, and natural pest controllers reduce the need for chemicals. However, insects can also spread disease or damage crops, so scientists study integrated pest management to balance benefits and risks. Protecting native plants, reducing pesticide misuse, and leaving small wild patches in yards help insect populations stay healthy.