So I have 10 muscovy ducks that I ordered from CountryHatchery so I know they are pure muscovy ducks. For the most part they will hiss and head bob or the girls will make little noises in their throat but recently the boys have been starting to try and breed the girls and one time when they had grabbed one of the girls I heard a small quack out of her. Is that normal? I thought Scovies couldn't quack?