I was just doing a little searching online and ran across something really cool! It's an idea for building an automated chicken door that will automatically open at sunrise and automatically close at sunset!
It's a really good idea because chickens can get eaten at night if their door is left open and a predator manages to make it's way into their run. Another reason it's good is so that you don't have to get up early to let your chickens out when the sun comes up or have to worry about being home to close the door at sunset. It's also a good idea for when you go on vacations.