Although Barn Owls nest upon the rafters of old barns their true nest site is the open cavity in large trees, usually where a limb has broken off. Barn Owls are in a different family than the true owls with longer legs and serrated middle toes. In the world there are 11 species, only one species in North America. They are one of the most abundant owl species in the world but because they hunt only at night they are often not seen unless a day roost is known. Barn Owls hunt in open prairies and marshes and catch rodents almost exclusively. Their heart-shaped face and orange feathering is distinctive. Their calls are loud screeches unlike the hoots of typical owls. Like the typical owls, the leading edge of their flight feathers are saw-toothed which enable them to have a silent flight. It was the Barn Owl that was used in experiments in the 1960s to learn that owls hunt by using their keen hearing and not by using their sight.