I would also like answers to this question. I've had chickens for 15 years and never had a predator get inside my run until last week. My run is divided and I had three 16-week-old chickens separated from the rest of the flock but within visual. I looked out the door to see what one of the dogs...
(1) Are you new to chickens / when did you first get chickens? My 20 year old daughter wanted chickens to show in 4H for her 9th birthday! We retrofitted the old wooden playset and have had chickens ever since but they are mine now!
(2) How many chickens do you have right now? 8 hens and 1...
Is your door a dutch door? I am thinking of doing that or just cutting a window that I can close up in winter. Would like to have the light in the winter so may just cut a window that I can put plexiglass in for the winter.