The Nymphalidae is a family of about 5,000 species of butterflies which are distributed throughout most of the world. These are usually medium sized to large butterflies. Most species have a reduced pair of forelegs and many hold their colourful wings flat when resting. They are also called brush-footed butterflies or four-footed butterflies. Many species are brightly colored and include popular species such as the emperor, admirals, tortoiseshells and fritillaries. However, the underwings are in contrast often dull and in some species look remarkably like dead leaves, or are much paler, producing a cryptic effect that helps the butterfly disappear into its surroundings.