Butterfly is an insect of the order Lepidoptera. Like all holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. The diverse patterns formed by their brightly coloured wings and their erratic flight have made butterfly watching a hobby.[citation needed] Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). Butterflies exhibit polymorphism, mimicry and aposematism. Some migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. In addition, a few species are pests, because they can damage domestic crops or trees in their larval stage. Culturally, butterflies are a popular motif in the visual and literary arts.