I recently changed out nesting boxes in my coop because my chickens were roosting on on/in them. I'm new to raising chickens and have a small flock of 12. My nesting boxes weren't covered but now I have ones that are. I also built new perches for them to roost. I went out to make sure they were in the coop so I could shut the door and not a single chicken was in there so I had to find them and move them each to the coop. Why aren't they returning and how do I fix this? My chickens are only 6 months old.