Now this comment has made me think: "we put the pop-hole down either when we get home or when we remember. and turf them out of the nest box."
Would be interested to know where your girls sleep.
We have quite a big hen house with a perch that they never use (they regularly use the perches in the run though) and all 6 of our girls sleep at the back of the house where there are 3 nest boxes. They seem to sleep (and poo!) in the middle or left hand box and lay in the right hand box or middle one.
Does this matter? Should we turf them out of the nest box? If so why?!