The peppered moth is a species of night-flying moth found in England and Wales. The moth has two colour forms, light and dark, which occur in different proportions depending on the background against which they are camouflaged. The light form is more common in rural areas, while the dark form is more common in cities. The peppered moth is an example of industrial melanism, a phenomenon caused by the dark form of the moth becoming more common in areas where there is soot from industrial pollution on the trees.