Why does a hen not lay eggs?

[pooponshoe]

I have read molting, stress, broody. Is it probable that a hen never, ever lays an egg? I have the cleanest looking white rock you could ever want, the other two are pretty dirty looking.

 

[Redfeathers]

I have a 35 week buff orp that has never laid an egg. I don't get the impression that she ever will either. I have heard that it does happen from time to time.

 

[turnerstar31]

how old are they. That can also be a factor

 

[pooponshoe]

They are just over a year old.