I have 12 chickens. I've raised them from day 1. They have a coop and a 10' X 10' enclosed run (for during the day while I'm at work) then they free range all other times. They ALWAYS go into the coop right around 8:00-8:30 every night. For the past two nights, one lone chicken roosts up on top of the run. Tonight I walked right over, picked her up and placed her in the run (she then walked over and got in the coop.) Is there anything I should be concerned about?