My grand parents and great grandparents had chickens running all over the farm when I was growing up. I don't even know if they ever locked them up at night or how they took care of them... there was just always a whole bunch of them scratching around. I used to love watching them - I'm pretty sure it's my grandparents fault I have my own now. Anyway, I know that they never gave their chickens oyster shells. And, I'm pretty sure they only got table scraps for feed (my grandparents couldn't afford chicken food for them) so how was it that their chickens egg shells always seemed fine. (At least, this is what I remember... it was eons ago. ) What would we do if we didn't have access to oyster shells today? I reuse my egg shells by baking them and crushing them up and giving them back to my chickens but would that be enough, over time, to keep their shells hard?