Owls are widely distributed birds of prey with large heads, flat faces, forward -directed eyes, hooked beaks, strong legs and sharp claws, and soft feathers. Most owls are nocturnal, although some hunt mainly at dawn and dusk. Most owls see well in poor light, but all see well in bright daylight. An owl's eyes are nearly immovable, requiring it to turn its head to look elsewhere. Some species can rotate their heads horizontally 270 degrees or about three-fourths of a circle. Owls are able to determine the direction of a sound source on a horizontal level by comparing the intensity of the sound heard in the two ears. Owls also need to know the vertical direction of a sound to be able to strike prey concealed by vegetation or snow.