The Barn Owl may be the best known owl in the world. The upper parts are orange-buff, spotted with dark grey and white. The underparts are white and the tail short. The male's breast tends to be more white, the female's more spotted brown. The heart-shaped facial disc is usually white. It is sometimes called the monkey owl because of its simian appearance. The long legs are completely feathered. Barn owls have a serrated comb on the claw of the middle toe, found elsewhere only in herons and some goatsuckers. Females are about 13 to 18 inches and are larger than males. Their eyes are large and dark; the wings are long. Their hearing is exceptional. They can locate prey in total darkness just by sound. Their ears take up nearly the whole length of the skull. They hiss, scream and utter a series of clicking sounds, but do not hoot.