I have 4 BO hens. They are around 38 weeks (an estimate, I was told they hatched in February). One hen started laying at 34 weeks and has been consistent ever since. Not a thing from the other 3. One has gotten large, just as big as the layer, and her comb is nice and red and growing. It's close to the same size as the layer but still nothing from her. The other two are smaller and still don't have the red comb. Are they just slow developers? Is there some point where I give up on getting eggs from them? I've threatened the stew pot, I've tried reasoning, I've bribed, but still nothing from the other three. Any ideas?