Owls are a group of birds that belong to the order Strigiformes, constituting 200 extant bird of prey species. Most are solitary and nocturnal, with some exceptions (e.g. the Northern Hawk Owl). Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish. They are found in all regions of the Earth except Antarctica, most ofGreenland and some remote islands. Though owls are typically solitary, the literary collective nounfor a group of owls is a parliament. Living owls are divided into two families: the typical owls, Strigidae; and the barn-owls, Tytonidae.