We are very new to raising chickens. We have 4 Black Sex Links that we've raised since 10 days old. They just started laying in early July. The coop is 16 square feet and the run is 40 square feet. They spend several hours free ranging in our fenced back yard on most days. They usually don't lay eggs until close to lunch time so I usually wait until they're done before I let them free range, otherwise I have to hunt for the eggs in the bushes. They have free access to food and water at all times and get plenty of healthy treats. Until yesterday, the girls have always gotten along great. Yesterday morning, when I was refilling their feeder, Cindy made a very weird squeak/honk sound. It looked kind of like a sneeze but the noise was really loud and weird, like nothing I've heard before. She did it a couple times but seemed fine. A short while later, I heard some squawking in the run and saw that one of the bigger girls was dive bombing and pecking Cindy. After seeing that happen a couple times, I let them out to free range hoping to give Cindy some extra space to get away. She kept trying to get onto the deck (we have it blocked off to keep it poop-free). I felt sorry for her and let her hang on the deck for most of the day. She had some black spots on her comb that I'm think may be dried blood. The drama started up again first thing this morning. Cindy paces along the run fence looking nervous and one of the bigger girls flies up on top of her to attack. I have 2 all black girls and two girls with some brown. Cindy is one of the black ones. There doesn't seem to be any issues between the two black girls. The brown girls look so similar that I can't tell if it's one or both of them that are picking on Cindy. What the heck is going on? What should I be doing? Is there something I should be putting on her comb?