I used to cover their old coop but now they have a bigger one with thicker wood (and I physically can't cover it because it's touching the run roof) so I don't cover it.
The coop doesn't have slits in the top, instead it allows air flow through the wood slats
I make sure I put a thicker amount of bedding so that they can cuddle together. Their run is already fully covered (and I can't let them out because of the bird flu!) I put less bedding on the run floor, so that they have a place to dust bath when I can't let them out.
I also give them a cup of...