Rita, that is odd that you haven't seen any adult birds going in or out. The hole in the birdhouse looks too small for Owls and I don't know of another nocturnal bird besides owls. I sure hope the nest hasn't been abandoned by whatever bird took up residence and laid eggs. Have you heard any more birdie noises today? It looks like the entry hole has been chewed a little. Woodpeckers seem to enlarge the entry holes to my birdhouses and sometimes they will nest and raise young in them while other times they just seem to enlarge the entrance hole but never move in.
We brought this birdhouse home from vacation one year and my husband mounted it on a tall cedar post in the backyard. Nothing has ever moved in that I know of but Woodpeckers (both Red-bellied and Downy) have worked at enlarging the entrance hole. I think the reason it's never been occupied is because the feeders are quite near this area.
And, this is an old Owl House that my sister gave me years ago but we couldn't mount it high enough for owls to use ... WP's enlarged the opening on this one too but never moved in and during the hurricanes of 2004, it was blown out of the tree and it sat on the ground for a few years and I'd see young squirrels climbing in and out of it as they played
