Chickens are smart. If you provide them with a place to live with food and water, they will be home every day before dark. If one should get out and can't get back in you will probley find it roosting in a nearby tree very close to the Hen House.
If you are planing to add a roster to your Hen House, be carefull not to get between him and the girls. You don't want him to consider you a threat. If you can get along with your roster you will find he makes a good watch dog. Letting you know when someone enters the yard, and he will act like a sheep dog, watching over and keeping the girls together. A large roster may be more than you can handle, consider a smaller breed.
Chickens will eat almost anything. In addition to chicken feed and scratch grain, I feed mine table scraps. I tell my friends and anyone that will listen to my chicken stories that I feed my chickens everything but chicken. I also say that cows and pigs are scared to walk through my yard because if my chickens see them they will be thinking "Lunch". Think about it. They eat plants and bugs, so you know they will like left over vegies and steak. I cut the left overs up into little bitty pieces. They come running everytime they hear the house door open to see if I'm bringing them a snack.
I know they are looking for a snack, but I can be home for an hour or more before I see my cats, and when I call my chickens they come running. I call my cats and they can't be bothered.