I have a bunch of young ducks - oldest are only 2 1/2 months old -large and beautifully feathered Rouens. The largest one seems to be either moulting or seems to be pulling all it's feathers off it's breast and stomach area. It's bald from lower neck down to between legs. I've seen it constantly preening itself in that area and think it may be pulling its own feathers out. If so, why? None of the other ducks seem to have this problem. It also seems to be having plugs of feathers coming out in various spots on back and head. Could it be moulting, the heat, something else? Gnats are really bad right now but haven't seen any lice or mites on anyone. What to do? They are outside with separate house, two pools, lots of food and water, grassy yard, plus extra greens fed to them. I feed them a mixture of layer feed, scratch & grains, black oil sunflower seeds, game cock feed (sustainer) that is all mixed together - same thing I feed all chicks and chickens.