nuthatch

Any of various small passerine birds from the genus Sitta, found throughout the northern hemisphere and noted for their unusual proclivity for climbing down trees head first.

• Nuthatches have rather a habit of entering houses through open windows, probably out of curiosity; and we owed to this habit a pet nuthatch, which became extremely tame, and used to take flies from our finger.
• The bird was in very faded plumage with only a slight rusty wash to the underparts, and had I not heard the call, I might have mistaken it for a Pygmy Nuthatch.