I'm pretty sure they don't eat them. Seams like they produced a good crop this year, and it does sound like your mowing rocks. I had black walnut jelly once, wasn't bad, a lot of work to get the meat out of the shell
It was in a farm workshop, I doubt there was a whole lot of art work going on in there, I think it's 50+ years old. The farm was built in 27. That part of the farm was a dairy farm.
Next year will be the end of the youth hunts for me, I've been doing it with my kids for 15 years, it's been a lot of fun, if you look close, thats a limit of ducks