Could you please post some photos of your nests, roosts, and how they relate to each other? Are the roosts higher than the nests? How easy is it to get to the roosts? How many chickens? How old are they? How long have they been sleeping in the nests? Are they sleeping in the nests or just visiting during the day? You say they are making a mess in the nests. Are they pooping in there or just scratching things around and out of the nest?
How old they are and maybe a photo showing the comb/wattles may help us see if they are getting ready to lay. That could be an important clue.
Typically if the roosts are higher than the nests they don't sleep in the nests but each situation is unique. You are having some issues. I'm trying to find out what is going on and try to come up with suggestions. That's easier to do if I have a better idea of what is going on.