excessive need for grit?

I have a hen and her two chicks that I have been keeping in town until the chicks are old enough to join the flock. She has recently developed an insatiable need for grit. I always give them free choice grit but lately she just wolfs it down. Her crop is loose I can feel lots of grit and food in it. She gets almost frantic when I go to her cage and none of the normal treats interest her. As soon as I give her more grit ( with some oyster shell in it sometimes.) she gorges on it. She is a nice sized bird neither fat or thin. Should I be concerned? I plan to treat her with ivermectin shortly in case its parasites, I am not sure if I should treat the chicks.

That is interesting nuthatch I am wondering if she has a bit of sour crop and is searching for grit to try and pass what is blocking it?

That is weird. Are you giving her chick grit or #2 grit? I wonder if she's really wanting bigger grit, if she's only getting chick grit to share with her chicks.

I have both chick grit and the medium grit. I have been giving her the biggest stones I see in the larger grit. as well as putting her in an outside cage so she can look for some natural grit. I don't have any large grit, last time I tried to buy the large grit at UFA they said they had only two sizes now. I may go the a landscape yard and buy some landscaping granite gravel. I did change the type of feed in the last month so I am going to go back to the pullet grower I used before. It seemed to agree with her before.