Three of my hens have developed bare spots above their tails. The areas are about the size of a quarter, perhaps a little larger. I assume it is caused by the rooster, but have done the following: Checked the hens for lice using a magnifying glass - don't see anything which resembles mice. Cleaned the area and applied Blue Coat. Gave each hen a new "saddle" The coop is 7 x 10 and has ten birds. The outside enclosed run is approx. 15 x 20'. I've never seen any of the hens picking on each other and there is more than enough room for everyone on the roost boards. Am I missing anything? Could this be something else other than the roo or lice which I need to look for? Out of 20 hens I'm getting 14.5 eggs a day so far this month, so they seem to be healthy and happy! (There are two sides to the coop - both the sizes mentioned above and the flock is divided between the two sides.) Thanks for any input!