How do you keep them out of the nest boxes at night?

My girls like to sleep in their nest boxes, which makes the bedding very dirty by the time they start laying eggs in the morning. During the summer they were using the roosts but now that it's cold they like to pack themselves into the small spaces (often more than 1 to a box). I've tried putting the perches "up" to block the entry, but that doesn't stop them -- they either knock the perches down or by pass them all together. They have the roosts, they have deep litter, they prefer the boxes. Any ideas?

And if I should somehow manage to block their entry into the boxes at night, how do I get them unblocked for laying short of going out to the coop at 4:00 AM?

 

Quote:When do you go in and do that? Timing is everything around here -- the girls go into their coop while I'm fixing dinner, by the time I can go back outside it's really dark...... will it matter if we can't see each other while I'm trying to move them?

 

Quote:The perches are the 2" side of a couple of 2"x4"s. Although it was cold last night, low temps have been in the 40s for the past week or two, so most nights they haven't been cold -- and even last night one of them was roosting on the window perch and it looks like occasionally someone digs herself a little nest in the litter. Since they spend all their time out and about, they haven't had time to get fat yet.

I think I'll try mdbucks idea tonight, since I don't have any milk jugs. Hopefully a few nights of being interrupted in their sleep will have them using the roosts again, at least until it really does get cold. Thanks for all the ideas.