It really depends on how you're keeping them. I keep them in a dry container and then keep them inside the coop away from anywhere that may get wet and don't have an issue. If they're getting wet you need to move them to a dry place. If they're already in a "dry" place you may need to add more ventilation to your coop
I don’t keep them inside their coop I keep them outside next to their water bowls. My ducks don’t get food at night, are OS needed 24/7 because I take them away after they are locked up.