I have 9 buff orpingtons who were good layers until about 3 months ago. They went through a short molt, didn't lose hardly any feathers. I feed layer pellets and crushed oyster shells. They all use the same nest box and two weeks ago one of them layed a paperthin egg. Of course they broke it. They are 1 1/2 years old. I am about to get rid of them. Do I need to have a rooster for them to lay and do they need to roam to eat grass to lay. I have them in a fenced in coop because of coyotes and possums.