So my two Brown Leghorns have been sleeping in trees for a while now. I tried keeping them in the coop for a week, the day I let them out that night they were in the trees again. Being leghorns they are pretty flighty. I just processed the four meaties that were bothering them and now I want to get the Leghorns to sleep in the coop, since winter is approaching and I don't want a couple of frozen chickens. They lay in the coop, they just don't sleep in there. Any suggestions would be greatly appreciated.