I have a blue tit box and a female has been sleeping it it for about two weeks now. Coming in at 5.30 each evening and leaving about 6.30 am. I looked tonight about 5.15 and saw a lot of small feathers all over the bottom of the box which weren’t there yesterday and the female didn’t come into the box to sleep tonight. Is this usual behaviour. I was worried that something might have got to her and left feathers. Can anyone with more knowledge help me please