How many legs do butterflies have?

The story behind the answer

Butterflies have six legs because they are insects—hexapods—with three pairs of jointed legs attached to the thorax. This is a defining insect trait. Some butterflies, especially in the brush-footed family (Nymphalidae), can appear to have only four because their front pair is reduced and held close to the body for sensing, making them easy to miss.

Bonus tip: Caterpillars seem to have many legs, but most are “prolegs,” not true legs; only the three pairs near the head are real. Memory hook: insect = six; “hex” (like hexagon) means six. If it’s a butterfly, it’s a six-legged hexapod.