I have 6 19 week old pullets. They are on layer pellets, free choice oyster shell and a few hours of free ranging a day. (bugs, toads, worms and small snakes are things I see them eat) I have at least one soft shelled egg everyday, this morning there were two. I have a feeling one of them might be from the same chicken, since its everyday, same time and place. Is there anything else I can give them to rememdy this?