@start living That must be so frustrating! A few questions:
1) How long have you had your ducks? You mentioned that at least a few were previously owned, was that ALL of your ducks, or just some?
2) The ducks who were previously owned: do they usually go in and out of your house, or do they seem to avoid going in altogether?
3) Did the previous owner use an automatic door?
4) What time does the door open at night? Could it be a bit too early for them to decide it's bedtime?
5) When does the door open in the morning? Our three Indian Runner Ducks typically lay around 7 or 7:30 AM, so we usually don't let them out until 7:30 or 7:45. I know that might seem late, but so far we've only had one egg laid outside of their house, and that was around 8:15 AM!