I have two hens that are over a year old and they get along quite well. I also have two six week old pullets, they are living in the house in a brooder right now. I have been taking the pullets outside for little field trips to introduce them to the yard, the coop, and the two hens. My laying hen is very aggressive when she sees the little pullets and attacks straight away. In two weeks I would like to be able to move the pullets outside permanently but I am really worried about their safety. What should I do? I would hate for my hen to kill one or both of my pullets. The coop I built is just large enough for four birds but I am really nervous to lock them all inside of it...Help!!