Looking for Cavities

For our year-rounders, February is definitely a month when nesting gets going.  And I expect these Brown Headed Nuthatches to be in the lead.  They're usually early even when winters are not so mild, and I can't see them holding off too long this mild winter.  The question is even more "where?" than "when?".  Brown Headed Nuthatches nest in small cavities, and we do have some possibilities on the property as well as some potentially inviting nest boxes.  Looks like I need to get out in the next week or so with binoculars in hand to take a census of cavities, and maybe even spot an incipient nest hole.  What a great project for a dreary February day!