I've been searching the forums but haven't really found this particular question. I've been throwing some oyster shell on the ground for my 4 hens for a couple of weeks as I transitioned them to layer feed, and just got my first egg today. I read about having oyster shell next to their food as "free choice" but when I left a small container out, it was GONE, lickety-split, and the container itself looked like they had played rugby with it, lol. Is there a danger with giving them too MUCH oyster shell? Can they overdose on it and have other problems, or will they stop when they've had enough? Mine are 20 weeks old and have been doing a 50/50 mix of grower/layer as I move them over to 100% layer feed (just about there). I also throw in a few handfuls of scratch twice a week or so, and move their tractor around every other day for grass, bugs and dirt. P.S. First egg was nice and firm, no shell problems.