Many derbids are easily recognized as such by their "unusual" appearance, while others are less distincive and difficult to identify. The family is characterized by a row of spines on the rear leg and a short segment at the tip of the beak. The head may be quite compressed in shape. The wings are variable. Some species hold their wings outward at rest as moths do, while others keep them parallel to the body. Some have simple wings, and others have very long forewings and short hindwings.