Hi, we had our first nest box, a terrace one, last year which thankfully was used successfully. It would appear we also had birds overwintering. On reading various posts on here is it now too late to clean them out? We had a look over the weekend and all 3 have dry nesting material from leaves and twigs to the wool we keep at the side of the boxes. Would it disturb potential new sitters if we were to remove this now? Or cause more issues if we were to leave it? I am sorry for asking, but need to make sure if we have gone wrong, this year we do it right! Many thanks