It looks like we have a House Wren that is seriously interested in one of the bird houses that Bill built and mounted on the tall fence in the back yard.
The diameter of the opening is important when building a bird house and this house has an opening that is exactly 1 and 1/8 inches across - perfect for wrens and chickadees.
There is no perch outside the opening as this encourages larger birds who may raid the nest.
Bill and I have gone hiking for the last couple of days - Wednesday in Palmer Park and today in Red Rocks Canyon. I have some new pictures and will post more tomorrow.