Rooster mating with ducks

[flwrldy]

I have a 13 week old easter egged rooster, named Rocky. He started crowing at about 10 weeks old, then about a week ago, probably last week or so, he started trying to mate with my two hen ducks, both khaki Campbell's. He doesn't try to mate with the hens, just the ducks. It makes them so mad too! They both peck at his feet and his legs when he does that ..
Is he just young and dumb, or just dumb?

 

[flwrldy]

I have a 13 week old easter egged rooster, named Rocky. He started crowing at about 10 weeks old, then about a week ago, probably last week or so, he started trying to mate with my two hen ducks, both khaki Campbell's. He doesn't try to mate with the hens, just the ducks. It makes them so mad too! They both peck at his feet and his legs when he does that ..
Is he just young and dumb, or just dumb?

BTW all the chickens and ducks are the same age.