In zoology, a scale (Ancient Greek: λεπίς, romanized: lepís; Latin: squāma) is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopterans (butterflies and moths), scales are plates on the surface of the insect wing, and provide coloration. Scales are quite common and have evolved multiple times through convergent evolution, with varying structure and function.
Scales are generally classified as part of an organism's integumentary system. There are various types of scales according to the shape and class of an animal.