My father in law has 4 plymouth rock and 1 rhode island red they are a bout 22 weeks old and have not started to lay yet. Is this common? We were told to remove the rooster and they may start to lay. Has anyone else heard of this? Does anyone know how long it takes for them to start to lay? I have 7 rhode island reds and they layed at around 19 weeks. Thanks for your help