This is my first flock of chicks. They will be 3 weeks old on Sunday. I have had them since they were 6 days old. I purchased them from a local home/small farm. I was told that the chick I am concerned about is a Lavender Orpington. She is one of the smaller (not younger, they are all the same age) chicks in the flock of 7. They are eating Dumor Chick Starter/Grower from Tractor Supply Company exclusively. I have alternated plain water, medicated water, and water with Save-a-Chick electrolytes and probiotics. Their bedding is pine shavings and they have about 1 sq ft per bird in their brooder box. I occasionally hear a chick/chicks "yell" as if hurt, but I am never able to get there in time to see what happened. I have a straight run, not sure who will be rooster/hens. I do observe this chick "cleaning herself" often, maybe more so that the others. All poop in the brooder appears normal to me. I've attached several pictures. Any advice/help would be greatly appreciated. Not sure why here skin/feathers looks different from everyone else. I was told I have 3 Americaunas, 3 Orpingtons, and 1 Silkie. I tried to get good pictures of how the skin and feathers look. What you see in select areas is pretty wide spread on the whole body.