Bare backs can be from the rooster, but bare buts, chest and bare around the big tale feathers suggest feather picking. It may be caused from crowded conditions (which is not your case), or something missing in the diet. 18% should be good, but if they are doing it, something is missing.
I had this issue and people on here advised Sunflower seeds and meat and it worked very well. Few times I gave them raw ground beef.
Pictures are not perfect. Please show more from the top, so we can see tail area, the back and some neck pictures.
Also continue checking for lice and mites as -tolkinboutchicken- suggested.
I had this issue and people on here advised Sunflower seeds and meat and it worked very well. Few times I gave them raw ground beef.
Pictures are not perfect. Please show more from the top, so we can see tail area, the back and some neck pictures.
Also continue checking for lice and mites as -tolkinboutchicken- suggested.