Every night I have to go into the coop and put my 8 week olds and 6 week olds into the coop. They go into the coop when I refill their food and water. They just run right in like no problem at all. But when its time for bed, the rebelious kids stay out. I locked them into the coop for 4 days when they first moved in and they still dont go in! Any tips?