Tammy, I have 7 hens, I let them run the 1/2 acre of dirt and stuff, is that the kind of grits you mean? they dirt bath and normal behavior. I did put the Oyster shells in a container next to their feed. I also put some in the feed to be sure they were eating. We boil eggs I will chop it up and feed those two by hand to see if they will take it. I don't know if GMO is in the feed? I don't give a lot of scraps, but gave them peas/corn and peaches yesterday. They like that. I wonder why none of the other hens have an issue just my 2 Brahmas? Thank you, I'll check out the bag on my feed.