Hi, I'm considering getting chickens, just 3 that would go in my backyard. I live in the city in Portland Oregon, which has a great chicken community. The one big concern that I have is the smell of chickens. I have friends with chickens that do not smell at all. They have droppings all over there coop and it smells fine. But I have also been around really smelly chicken coops. How often would I have to change the bedding of my coop? What is the common amount of time in between changings? My other question is about vacation. If I went away for many days but left my chickens in their enclosure, which would be a run that is fenced in on all six sides (top and underground), with a coop inside would they be okay for an extended period of time? Thanks!