Bird Bottle, and Wrens, Again

For several years now I have been doing my utmost to attract birds to a Colonial Williamsburg-style "bird bottle" with varying results.   We saw considerable success in 2011 when a family of Carolina Wrens took up nesting.  Then, nothing at all last year.  But the wrens are back.  Their messy shove-debris-into-the-hole style of nesting is showing clearly even though I have yet to see a bird making the transit to the bottle.  That will come.  They have clearly been attracted to the warm, yet shady spot above the garage door and do not seem perturbed by the occasional movement of the door below.  For my part, I'm simply glad the rascals are using this unusual nesting space.  We shall see what comes.