What is "insect"?

Insect refers to a diverse group of arthropods characterized by their three-part body structure, including the head, thorax, and abdomen, as well as three pairs of jointed legs. They are the most abundant and diverse group of animals on Earth, with over one million known species. Insects are found in virtually every habitat on the planet, from the depths of the oceans to the tops of the highest mountains. They play important ecological roles as pollinators, decomposers, predators, and prey. Some insects are considered pests because they damage crops and spread diseases, while others are beneficial because they help control pest populations or provide valuable products such as honey, silk, and dyes.