Della, the cat who adopted dinner

I highly doubt they can even suckle the milk let alone digest it, throws the credibility of the whole story out the window for me.

Baby ducks don't drink milk, they mostly just eat insects and then after a few weeks start eating more plants. Therefore the mother cat is pretty much doing what a mother duck would do, keeping them warm and safe. (We have a farm and while we don't have any cats nurturing ducklings they get along alright and just do their thing.)

I know baby ducks don't USUALLY drink milk, what I'm curious about is whether or not ducks could digest it if they did happen to drink milk. Would they be ok? Or would they get symptoms of lactose intolerance?

As far as I know they can have some milk/dairy but not much because most birds are lactose intolerant to some degree. The worst symptoms would probably be diarrhea.