I have 7 Rhode island red hens no roster and they will be 3 this summer, about four weeks ago i had to remove one of the girls because she was beat up so bad. Last night when i went to close them up for the night another one was laying in the corner of the coop and they were taking turns beating her up? Do the old girls get aggressive as there egg laying days end? They have a 16 x 24 foot play area and nothing has changed in the coop except the aggression and egg production. (2 or 3 a day)