Many of my hens have a spot where their tail meets their back where the feathers are missing. Some are worse than others. Poor Shirley (pictured here) is the worst. Is this molting or are my roosters doing this to them??
That is probably from mating, but some people without roosters in their flock have similar problems because of a nutritional deficiency or unknown cause. I would consider purchasing some hen saddles, getting rid of the rooster(s), or increasing the amount of hens you have--any of those things should help your hens grow back their feathers.
I have 30 chickens total, 2 of whom are roosters. I had always "heard" that this was a good ratio of hens to roosters. My roosters are one and a half years old. What's the deal?