I've have an egg mystery. The hen is banty and the egg is about the size of a marble and is dark brown. I have 7 banty hens and 5 reg size hens and when they all lay I have 11 eggs my Ameraucana hen hasn't laid yet and I collect 11 egss but every one and then someone lays a teeny brown egg. Who could it be. These are my banty girls 2 silkies,3 OEGB's(blue/black/self blue),black cochin, seabright I've search online but I can't find anything the mystery part is I've caught just about all of them leaving the nest box and I've hatch eggs from 2 of them.