I just brought one hen in from the coop - she was laying down on the floor - the others are on the roost. She looked dehydrated (comb 'dry' in appearance and flopped over vs standing up as usual). Couldn't get her to drink, but noticed very tiny bugs in her feathers. Was hard to tell if the bugs even had legs, but they were moving through her feathers - they appeared to be long and a dark grey in color. Is this mites??