Hello! I have 6 ducks who are almost 4 months old. There are 4 females and 2 males. One of the males (Humphrey) is a small runner duck and the other (Kenny) is a large jumbo pekin. Starting a couple of days ago, the runner duck has been really aggressive toward the pekin. He has been chasing him and jumping on his back and biting him as well. I am starting to worry that the pekin may get injured. I know this is a display of dominance, but will it stop eventually? Or is there something I should do? Any suggestions would help! Thank you!