I returned in a few minutes armed with a bucket of a very weak Clorox solution, rubber gloves, and a plastic bag for the nest. Just as I approached, a bluebird darted out. “Hmmm,” I thought. “Maybe today is not the best day for housecleaning. Maybe that nest is still in use.” So I turned my attention to another house in the yard. I peered in and it was just a mess – twigs arranged in no particular pattern, kind of trashy, clearly not a bluebird nest. I pulled it out and noticed five small brown eggs hidden in the cup. “Oh, no! Not again! I think I better leave this one alone, too.”
Later I thought about what my impatience could have cost. There are now five bluebird eggs in the nest and the wren has returned to her brown eggs, so things seem to be OK. From now on I will let nature take its course – no housecleaning until fall!