At my local bird store I actualy bought a round plate that is placed over the hole so squirrels can't chew the hole and make it bigger.
I have a problem with the house sparrows using my houses. But since I can't seem to attract bluebirds, I'm happy with the sparrows using the houses.
I did put the metal plate on one of my bluebird houses but the sparrows can't get in it so we are thinking of removing the plate.
Quit stuffing your face and face your stuff.
Be yourself, everyone else is taken.
I think therefore I am dangerous.
Don't make excuses, make changes.
See my photos on Flickr. www.flickr.com/photos/blackheart904/