Cute birds - but if I am reading your post correctly it sounds as though your birds are sleeping in the nest box? If that is the case, this is a habit you want to break - especially now that the eggs are coming in as the last thing you want is nest boxes full of poop (they expel a LOT of waste in the overnight roosting hours due to the amount of digestion that takes place at that time while they are in one, set place). If this has been something that you have allowed until now it is going to take a bit of work to change their routine and get them roosting on the roost and using the nest boxes for what they are meant, to nest in while laying eggs. One approach is to block their access to the boxes about half an hour before "bedtime" so that they can't get into the box and will look for a different place to sleep - thus finding the roost. Another option is to go out at roost time and physically lift each bird out of the nest box and place them on the roost - eventually they get the idea of where they are supposed to be when it's time to settle in for the night. While nest box sleeping is not unusual for young birds to develop a habit of doing, sometimes the cause is more to do with the layout of the coop - can you tell us a bit more (or show a photo of) the interior of your coop?