I know I'm crazy for thinking about winter when it's over 80° outside, lol, but I want to be prepared. I only barely got their permanent pen built last year before the snow hit (and I mean HIT - almost 2 feet...power was out for days). Since I was rushed, I did an admittedly poor job on their house; it sufficed, but I'd like to rethink things this year now that I know what is helpful and realistic. Right now I have 3 boys and 2 girls (which I know isn't ideal), and I don't believe I can lock them all up together - chaos would ensue. They will need separate houses, or at least a divider. One large house is just too big to reach through to clean; I learned this with the house I'm about to dismantle. If it's not easy to keep up with, I probably won't do it, lol...that's just me. I like to make things easy on myself. So I was thinking about a pull out tray made from a plastic storage tote. Then it hit me - why not just make the house out of a tote? Turn it upside down, cut an entrance door in the side, and throw some bedding inside. Cleaning would be as simple as flipping it over, removing the lid, and dumping into a bag, then hosing it off if needed. They could come and go as they please instead of being locked in all night, and it would be water tight (unlike their current house which leaks, ugh). From what I've read on here, I feel pretty confident that they would stay warm enough - I think the coldest it got last year was in the upper single digits for a week or so. So, after all of that, my question is: how much space is recommended for a mallard in a house that they can leave freely and probably only use on very cold nights? Does a little over 2 sq ft per duck sound good? For those of you who only have larger birds, keep in mind (with the exception of Mr. Chunky Duck aka Bullwinkle) they are only a little bigger than a football. Oh, and safety isn't an issue at all. Their pen is super secure; it's covered top to bottom with an underground apron, all in 1/2" hardware cloth. Cost quite a few hundred dollars, but the peace of mind is worth every penny! I haven't locked them up in their house at night in months.