I had a couple of 60ft conifers taken down this year and discovered the birdboxes in them had not been used over the years. "Not surprised this one's not been used," I thought, "it's busted". So I held it together with Gorilla tape and temporarily stuck it on a garden wall by the shed while I got round to fixing it. Within a couple of days a wren had started building a nest in it. It finished it but the wren never nested in it so I thought he'd fallen victim to one of the magpies or cats which roam our garden but then discovered they can build up to 10 prospective nests, then the female chooses which one she fancies. Obviously ours was not up to scratch.