My mallard ducks are acting very strange today. This past weekend, I cleaned their coop on Saturday, removing all of the old bedding and putting in fresh bedding. They hardly came out of the coop today. They didn't drain their waterer as usual, they didn't swim in their small pool as usual. They just spent the entire day inside, even though it was a nice sunny day today. They did come out into the yard when I opened up the gate this evening, and they seem healthy. Could it be they like a clean coop that much? I use a deep litter bed, and this was my annual cleaning. I add hay to the bedding every 3 days or so, and the coop never smells or is wet etc. Just wondering if anyone else has had a similar experience.