I did take a very quick peek in the box tonight when I didn’t notice them around. It was windy so I barely opened the box, I just needed to see if anything was in there. She had an inch or more of stuff, didn’t open it far enough to see what the stuff was but there is definitely a nest! Yeah! From what I am reading it is not very common for White Breasted Nuthatches to nest in a birdhouse so this is pretty cool. She was in the box most of the day, would peek out here and there and sit at the hole. Never saw her bring anything in at all so I am really not sure if the nest is done or what, didn’t look for a nestcup since I barely opened it and closed it pretty quickly too. Not sure if the WBNH do the caulking thing or not, I hadn’t read that on them, just the sweeping. I know red breasted nuthatches spread pine sap around the hole of their cavity to deter other birds and predators.
Donna in WI