Sorry for being a power mod, your post is now pinned. If there are problems with it: tell me
Edit: i think for now it is not much of a problem and it educates people that there is better food than bread (which is bad) but in the future if i continue to pin posts it could get ugly for a people to come back and see the same posts every time
It adds calcium to their diet. Birds in the wild will sometimes eat the shells of their own eggs after they hatch to replenish the calcium lost laying said eggs.