The facial disk is greyish, and the eyes are large and bright yellow. The bill is black. The legs and feet are light buff and heavily feathered. They tend to depend on plumage for camouflage when roosting in foliage, but when threatened, a Saw-whet Owl will elongate its body in order to appear like a tree branch or bump. They are silent at other times of the year.
Territorial calls are series of short clear notes .
This sound has a resemblance to the whetting of a saw. They will also range through wooded areas and hunt in heavy shrub cover. When prey is plentiful, a Saw-whet Owl will kill as many as 6 mice in rapid succession, without consuming any of them. When food is plentiful, it is common for only the head of each prey to be eaten. Deer mice being the primary prey, followed by shrews and voles.