I got all my ducklings at Rural King yesterday. The girl said that mallards and rouens look exactly the same so I told her to just grab one of them and the rest I picked smaller KCs in the hopes that they would mostly be girls haha. Came home and did some searching, my son said he is Rouen because his chest markings coincide with the Rouen duckling on Hoover's site and the mallard had a lighter chest. I found a thread here that talked about two stripes on the face and started really comparing Hoover's pics side by side in Photoshop LOL.