I gave my flock that just started laying oyster shell this morning... about an inch in a small pie pan. They just started laying about 3 weeks ago. I give them yogurt periodically. They have all had great shells, even for new layers. I just gave them the oyster shell because I read I was supposed to. That being said, within about an hour, they ate all of the oyster shell. Is that bad for them??? Is that too much calcium? They have plenty of food and clean water. I give them treats every few days, which they love. I wonder if they thought it was a treat and went to town. I thought I had read that they would eat what they need of oyster shell. I did not expect them to eat all of it that fast. I appreciate any thoughts!!!