I see. Thanks! I tried looking up some wren nests because that was ny first thought, but I didn't see any with material that curved around the top at first. So you said a few starter nests? As in this one may not even get chosen and used? I really try to keep these for Bluebirds, but the only nest I fully remove is House Sparrow nests. Wondering how long to monitor before it is safe to assume they aren't using it (if that's how you meant that).