How many legs does an adult butterfly have?

An adult butterfly has six legs.

Butterflies are insects, and the defining body plan of an insect includes three pairs of jointed legs attached to the thorax. In most butterflies, all six legs are present, although their appearance and use vary between families.

The apparent exception is the brush-footed butterfly family, Nymphalidae. Its members often hold their small front legs against the body, so observers may think they have only four legs. Those reduced forelegs are still present and are used mainly for sensing and grooming rather than walking.

This is a common mix-up with another butterfly feature: wings are attached to the thorax too, but wings do not count as legs. Caterpillars have a different arrangement, with true thoracic legs and additional fleshy abdominal prolegs.