I am new to raising chickens. They are 30 days old and still in the brooder. I am building the coops and was planning to put in automatic doors but started wondering if they would get trapped outside if the door closed before they got in. So do they need to be trained to go into the coop or will they just know to go back there when it starts getting dark? I am building 2 coops under the same roof but will be seperated. 1 for my laying hens and 1 for breeders.