We have 4 runners, 2 male and 2 female that are a little over a year old. The females hatched four babies in late july. The babies are getting bg, however now there is a male from the original 4 that is getting MEAN and Aggressive chasing the ducklings non stop and pecking their heads and backs, trying to keep them from the food. I don't want to have to remove this male, any suggestions????