We needed a propane delivery so I went out to collect this year's Carolina Wren nest. Have never done that before but over this particular summer I was puzzled to discern no nest shape through the kitchen sink window. That was a first although they nest there every year. As soon as I opened the lid of the propane tank the mystery was solved. This is a deep nest pocket. The birds seemed to disappear into dark nothingness because that's how their sanctuary was constructed. The long whip-tails of dried branches amaze me. These are very small birds. Am astonished I didn't notice at least one gathering addition along the way. Fascinating!