Northern Saw-whet Owls are almost entirely nocturnal, spending the day roosting quietly in dense foliage. At such times, they are extraordinarily tame and may be approached closely or even handled. At night this tiny owl becomes a rapacious hunter, preying on large insects, mice, and other small rodents. Though widespread in Canada and all of the northern and western United States, its distribution is spotty. This pattern may be attributable to uneven or inadequate food supplies in areas with severe winter conditions.