I was going to suggest this too, but I did see your follow up.
I have a large house sized motion light on the coop, right by the door, and then something similar to these LED ones at each gate (plus one on our back door which is really helpful).
http://www.amazon.com/Mr-Beams-MB33...TF8&qid=1403310690&sr=8-6&keywords=motion+led
I think it helps with predators.
What about stupid birds that don't roost?
Turns out that guinea fowl that was significantly infested with mites spread it bad in the coop when it was here 5 days ago. The turkey and her chicks that were brooding in the corner of the coop have visible mites. One of the babies died today (not related to mites), and when I picked it up it had mites on it, sucking the blood. UGGGH. I think I'll be getting up at 0300 to Frontline everyone tomorrow. And likely do an entire coop clean out. I had got rid of the mites in October with a lot of work. I do not want to go through that again.