I just bought some ducklings from tractor supply and I was able to hand pick them and I saw what I thought were mallards so I didn't get any of them I picked different kinds. They women said that they were Rouen instead of mallards how do you tell the difference when there so little?

yeah they do look quite a bit alike...and sometimes the rouens 2nd stripe are a little light and they can look almost like mallards so they can be tricky. Lol I'd only buy them if they are clearly marked with the 2nd stripe, just to make sure! 
