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 colorful 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 under-wings 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.