Well, we caught the rat that was killing our ducklings. He managed to get another one before we did though. So that's 4 birds lost to one rat. Gonna have to go nuts with the chicken wire.
I'm so sorry! Well now you know. Chicken wire isn't rwally the best to use to keep your ducks safe especially from rats. Hardware cloth is a much better option. I would use hardware cloth to keep them safe overnight and start locking them up very well. I also have mine in my yard and they free range during the day but at night they are locked up in their house that has a lockable latch and all openings are covered in 1/2 in hardware cloth. Since its going to get cold soon food is going to start getting scarce and your ducks will look like easy meals.