Hi Everyone - I"m very new to chickens. I have 8 28 week old birds and two have started missing feathers on the backside right before the tail. One of them looks better, but the other has a bald spot with a nasty scabby/bloody spot. I put neosporin on it yesterday but today, there is the swollan bump that is blushish in color next to it. I know she's getting picked on, but I don't know what this is??? Help?