We have a solar powered auto door with a manual option. using the auto door the light goes on within a specific timeframe before the door closes. Once they see the light, place them in the coop and let the door close so they get used to the light meaning "come home" followed by the door action. To ensure no one would quickly bolt out or stand in the frame, we close the manual door (located on the outside of the auto door) and wait for the auto door to close, then reopen the manual door. This process only took three nights before they 'got it'. Now that it's ugly hot and humid at night, we leave the door open all night for extra air but they cozy up in the back until early in the morning before dawn when I find one of them sleeping in the door way. She is the one who usually shows signs of heat stress first.