Bus doesn't care.... he's been known to plop down in the slag/gravel in the driveway, which makes me hurt on his behalf. I guess he generally prefers a bed in the house, unless he's hot, but outside, he doesn't care what surface he's on. Annie pretty much refuses to lay on any hard surface, all her life, but especially in old age. In fact, when I occasionally put them somewhere that she can't find an appropriate soft spot, she waits til Bus plops out, then sits/lays on him like a couch or bed.