I am new to owning any type of birds. We have 10 New Guinea hens that are about 10 weeks old. I started noticing they all are missing feathers on the back of their necks. I've read about them pecking at eachother but I don't ever see them being aggressive towards eachother. I went out for the second time today to checkbon them and one of their faces looks raw and bloody. Someone please help I'm not sure what to do!