Look under the wings for tiny blue specks. They are blue bugs and are small parasites. To get rid of them sprinkle 5% Sevin dust under the wings. It won't hurt the chicken. It sounds like what you might have. They are so small they might look like dirt but are closer to the size of seed ticks...
Hello ginger67, I am new to this forum but have had chickens before. I love them and plan to get a few to free range in my yard. Where did you get yours? I'm in the central part of Texas and would rather not have babies but just a few hens or pullets.