My three ducks sleep in the henhouse primarily, but they also have a tendency to come out and waddle around in the pouring rain, snow, and whatever other weather we might be having. They come out of the henhouse at night and waddle around if they hear anything interesting at night, and sometimes eat and drink and quack, too. Doesn't bother me--they're large, robust ducks and if they want to get get wet or hang out in the weird weather, they can. They really don't seem to be bothered by it, and they have warm, dry shelter if they choose to use it (as they usually do, albeit in shifts). It's almost like they take the night shift of guarding the coop, while the guinea fowl guard the coop during the day.