Automatic chicken doors: fox proofing a coop for when away or late

I really like my ADOR1 door because it is a simple design but solidly made. You can adjust the settings so the photo eye starts a timer for however long at sundown to give your girls enough time to get into the coop. I have to see how long the battery lasts in my environment, but I might convert over to a rechargeable battery/small solar panel system.