Yes, a fly is an insect. Flies belong to the order Diptera, characterized by a pair of wings and compound eyes. They are classified as insects because they have a three-part body structure: head, thorax, and abdomen, along with six legs. Flies play a vital role in the ecosystem, acting as pollinators and decomposers, though some species, like houseflies, are known for spreading diseases. With over 120,000 species worldwide, flies are among the most common and diverse insects. Their adaptability and rapid reproduction make them fascinating creatures despite their often pesky nature.