I am getting a new house for my 2 ducks and 2 geese. the house is 8x8. It will just be to keep them safe at night. It has a door and a window on two sides. It his wired for lights and outlets. It does not have a floor in it. It will be on a foundation that will be as preditor proof as possible. My question is this: Should I leave the floor just dirt? Should I put down sand or something else. Will need straw on the ground for winter but for cleanliness and comfort what would be best?