How do you relate any of this to them getting into the oyster shell? How is cross-beak related to too much calcium? I don't know what the symptoms of the other three were. I don't understand.I had chicks get into the dish of oyster shell unbeknownst to me. Out of six chicks, one died, two had to be culled, one developed cross-beak at two weeks old, and the other two are fine.