I have a year old male runner cross who has suddenly become extreamly aggressive toward one of my female ducks, pancake. he literally chases her down and pins her on her head and back of neck but doesn't always try mating. Pancake is now so scared of him she won't go outside with the others and will only stay in human company. only way to get him off her is too pick him up but he still hangs on to her. It's horrible! Does anyone no why peanut has started doing this and if there is a solution. I hate taking him away from the othe 3 females as Pippa his sister gets extreamly upset but penny gets upset when pancakes comes inside to hide. Thanks in advanced! A very stressed duck owner!