We have a buff orp. roo with a bo hen, two speckled sussex hens and they all cram themselves into the nest box at night!!! I couldn't believe it when I first saw it! Here I am slaving away all day long trying to keep them from dying in the heat and then at night they almost kill themselves by squishing into the nesting box!!! Crazy things! I have taken to removing the nest boxes bottom so that they can't and that seems to have dealt their plan a final blow!