I've been reading in the Coops & Run Design forum about using pea gravel or sand in runs. One concern I've seen raised is that sand gets very cold in winter and wouldn't be suitable for colder climates. The folks in that forum are concerned about chicken feet. I know ducks are more cold hardy and I know they still hang out on ponds and shorelines with sand in very cold weather. My question is, are there folks living in really cold climates who use either sand or pea gravel in their runs? Have you had any issues with it? Also, pea gravel was appealing to me because you can hose the large amounts of poop off with periodic hosing. However, in winter we shut-off the outside spigots. I was thinking either straw on top (basically deep litter in the run) or using sand and still raking it in winter. Your thoughts?