What is up with these pullets??? Our chicks will be 17 weeks old on Monday and they are still not laying. I don't know if it is the heat, stress (we have a train) or what??? How much longer should we wait? They are still on starter/grower feed, I am not sure when to switch them. I am back down to buying 25# bags again 1 at a time. Is there anything else I can do???