We're building a coop and run for about 5-6 chickens. The coop and run will be on extremely sloped ground, so we're planning on putting the coop/run on a raised plywood platform and drilling holes in the floor for drainage. We're looking for a type of bedding to use for our run that would drain well, not smell, and not fall through our drainage holes (the size of which may vary, depending on the bedding we choose). We would also prefer a bedding that the chickens might enjoy scratching around in (as they will be cooped up in the run for most of the day, until we can let them out in the afternoon). Are pine shavings a suitable bedding for our needs? If not, what makes it unsuitable? We're also looking for advice on the size of the drainage holes.