I adopted a couple of Rouen ducks a couple of weeks ago. The lady whom I got them from said that they were laying eggs but stopped presumably due to the hot weather. I took them in and fed them waterfowl feed, which is basically flock raiser type of feed. I offered oyster shell and grit. Today I was surprised to see that they are molting. They seemed to be healthy, if still a little skittish. Did I feed incorrectly? Or is this just their time to molt? They're about a year old.