Thats interesting Jerry, maybe the pieces are too big? I use crumbles and once I had a chick choke on a crumble and I had to get tweezers and scrape the food out of its throat.
I just happened to be watching the new chicks in the brooder when I thought this chick was gasping for air, I picked it up and it kept gagging.
I looked in its mouth and the crumbles were stuck in its throat, I grabbed the tweezers and got it out but I am sure it would have died.
Ever since then if I hatch chicks I grind the crumbles up in a blender or pour hot water over them to make mash.
On those real cold mornings I make hot mash for the whole flock and they go wild for it.
Once they are a couple of weeks old I give them the regular crumbles again without grinding them up.
So the only thing I can think of why Momma hen is doing that is because she knows they are too big.
It sounds like she is making mash for them.