A friend brought me two new hens today. She set them out in the shade of the yard in a cage. We didn't know it and let the dogs out when we got home. They killed one of the hens before we knew they were there. I'm so sad. She was beautiful. We got the other one into the run and coop area. How will they all learn to get along. I have two other hens and a rooster. One of my hens is being mean to little Dumpling, pecking at her. What should we do? She is about 3-4 months old.