From June to September, my 2 ducks were in a temporary enclosure that just consisted of their large duck house and a small pen. If not outside in the pen,they were sleeping in the house. Now they are in a huge run, shared with chickens. And now I have 3 ducks. But I have noticed they are never in the house, (the house stays clean and dry inside). 2 weeks ago at lunch I did see the one duck inside but thats it. today I snuck back to check everyone out and I saw them sleeping outside by the water. Is this what ducks do? Is it because the run is bigger that they don't go into their house?