Another one of our chicks (a jersey giant chick) dropped down on the ground and started scratching its head both sides while screaming. We immediately separated it from the other chicks and have it in a "sick tank." I've given it vitamins and cleaned the brooder and put very little dust in there since I thought perhaps mites. It's still doing it and my boyfriends Mom suggested it could be something else. Anyone have any ideas what could be wrong with it?