I might have to remove my light, my girls are so stressed, or at least acting stressed about it. I can't get them to lay in the coop anymore and have to chase them in to it at night. It will be pick dark outside and the light to the coop is off and I still can't get them to go to bed. When I come to let them out in the morning they fall over each other to get out and the coop is a mess.
That does seem like a stress reaction. There is something about the coop that they don't like. I would start going through the list of things ie, space per bird, ventilation (high and low), placement of things, critters, etc Once a chicken homes in on a nest, coop, roosting place, they won't willingly give it up without a huge fight so it does seem odd that they have ditched the coop.