I have an almost two year old Buff Orpington. Lately she has been acting really mean to the other chickens and stopped laying eggs. Today I watched her actually mount another hen. I thought this hen was just molting, but it looks like her feathers are actually being pulled out by my Buff mounting her. She was very late to start laying compared to my other hens, and she layed soft eggs for months. Is this normal? She is obviously the top of the pecking order because she is so fat, but why is she mounting my other hens? Stopped laying?