I don't quite know what to think about this. My front blue bird pair laid 4 eggs for their second nest around July 1 (I took this picture July 3).
I was then gone for most of July but I calculated that by the time I got back the babies should have hatched around July 15 and should be ready to fledge soon. Yesterday I watched the nest box but didn't see any activity. This morning I noticed the mom go into the box and not come out which is more like incubating behavior. I couldn't stand it anymore and went to the box and took another picture and this is what I found
There is no way that the 4 eggs hatched, fledged and she was ready to do a 3rd nest which I almost never get here. Do you think the 4 eggs didn't hatch and they pushed them under and started over? At any rate she is incubating so we will see what happens!