My husband is designing and building a coop for 7 chickens we'll be getting this spring. We live in the Pacific Northwest, near Portland. I've asked him to build a coop with a covered run because we get so much rain. He would like a tractor so that they can range more while being safe, and so that they don't ruin the grass in one spot. I'm not convinced we need a tractor. It just doesn't seem practice for the 5 months a year when the ground will be too wet to move it. I don't want my chickens living in a muddy swamp. Any suggestions or ideas?