The tiny structures covering a butterfly’s wings are called scales.
Butterfly wings are transparent membranes supported by veins, but their familiar colors and patterns come largely from thousands of microscopic scales. Each scale is attached to the wing by a small stalk and overlaps neighboring scales like roof tiles.
Some scales contain pigments that absorb or reflect particular wavelengths of light. Others create structural colors through microscopic layers or ridges; the vivid blue of many morpho butterflies is a well-known example. Scale arrangement also helps produce camouflage, warning patterns, and eyespots.
Scales can rub off when a butterfly is handled, but losing some does not immediately destroy the wing. The wing itself is living tissue only during development; after emergence, the adult wing cannot grow or repair major damage.