What insect order includes butterflies and moths?

The insect order that includes butterflies and moths is Lepidoptera.

Lepidoptera is one of the best-known insect orders, recognized especially for the scales covering adult wings and bodies. Most adults have a coiled proboscis for drinking liquids such as nectar. Their larvae are caterpillars, which usually have chewing mouthparts and often feed on leaves or other plant material.

Butterflies and moths share a complete-metamorphosis life cycle: egg, larva, pupa, and adult. A butterfly pupa is commonly called a chrysalis, while many moth caterpillars form a silk cocoon, although neither distinction applies universally. The adult emerges from the pupa with a completely different body form from the caterpillar.

Butterflies and moths are not two separate orders. Butterflies are a specialized lineage within Lepidoptera, while “moths” is a broad, evolutionary grouping that includes most lepidopteran species and is not a single formal clade. Day-flying behavior and clubbed antennae can help identify many butterflies, but exceptions mean they are not perfect rules.