Why do butterflies have powder on their wings?

The wings of butterflies are covered with small scales. These tiny scales produce magnificent colours and pattern by optical interference of light. The tiny scales reflect and disperse light producing the brilliant colours. When we touch the wings of a butterfly these tiny scales come out in the form of powder, thereby leaving the surface of the wings colour less. Even moths have powder on their wings.

Funny Logic

• Because their faces are too tiny to apply powder on.