What Breed of ducks is this?

[giselaespitia]

I just got 2 baby ducks from Tractor Supply. Wanted to see if anyone knows the breed? Also, what can I look at to see if they are male or female?

 

[HoneyBeeHomestead]

Hi, they look like Rouens. And they are too young to tell male vs female. Once they get older, males will have darker heads and a curled tail feather. Females make a "quack" sound, while males sound raspier.