It won't be fancy but it will work! Just get some hardware cloth and put it wherever there are spaces something like a weasel can get through and you should be good to go!
I made a pallet shelter for mine in the run for during the day for shade and when it rains. One of the maintenance guys at...
If you can get some (5-6) pallets they might work as long as you've got a piece of plywood for the top and bottom. Take some scrap wood to fill in the spaces between the pallet boards. I wouldn't have the ducks be directly on the ground but a pallet is a good hight for them to get into with a...