I have a flock of nine. Six are a few weeks younger and go into the coop at night to roost just fine. Then I have my three girls who are a few weeks older. One (an easter egger) seems to be the babysitter/watch chicken/mama and waits for everyone to go in. The last two are Dark Brahmas and will not go into the coop at night. They sit at the top of a little platform that leads into the coop. My run is not secure enough for chickens at night so for 2 weeks now I have to push them in, then my easter egger follows. What do I do to get them to go in? The coop is 4ft.x 8ft. and well ventilated. The design is below. I've read that some chickens don't like to go into the coop if it's dark so I added some string lights up near the top. I switch them off once everyone is settled to avoid them giving off too much heat. Lastly there are 3 2x4 roosts. I don't know the exact measurements but can check tomorrow. During the day they roost on branches in the run. Should I try to get some branches in the coop? I have an auto door that I cannot use as I don't want these three getting shut out. Any advice would be greatly appreciated. I can upload pics if it helps get a better sense of the setup.