I have 3 buff orpingtons 2 light brahmas and 10 meat birds all 5 weeks old. i open the door in the morning and all the pure breeds and one meat bird come out. at the heat of the day i put all the birds out so they can get under the coop to stay cool, but at night the meat birds wont go in, then the pure breeds feel safe with the big birds and wont go inside. How can i get them to go inside at night?