An insect is a small, six-legged creature that belongs to the class Insecta. They are characterized by having three main body parts: the head, thorax, and abdomen. Insects are the most diverse group of animals on Earth, with millions of species identified, including beetles, butterflies, and ants. Insects play essential roles in ecosystems, such as pollination, decomposition, and serving as food for other animals. They can be found in nearly every habitat, from forests to deserts. Some insects, like mosquitoes, can also be pests, while others, like ladybugs, are beneficial for gardens.