I just ordered my first chicks, 6 dual purpose breeds that will be here in the spring. I'm trying to figure out whether to build a permanent run or a movable one. I have an acre of land but its unfenced, and there are lots of predators, raccoons, possums, coyotes, hawks ect and stray dogs. Also a road on one side. Are chicken tractors practical for 6 hens? The designs I saw dont look like they would keep out a determined dog. Couldn't a dog just dig under the wire? If a permanent run is better, how often do I need to clean it out? Any thoughts?