According to the lady that I got my KCs from, she said that ducks are much happier in a bigger flock. I have six ducks, and they all hang out together. Mine are also about 3-4 months old. They are not noisy, nor do they bother my chickens. I think a few more ducks with your one drake would be great! Apparently, I've heard that a good ratio is about 1 drake to 3-5 ducks, I think.