I am fairly new to the duck world. I have chickens and I know they are completely different from each other. I have duck eggs in the incubator right now. How old do baby ducks have to be to add them to a flock of older ducks. There will probably be an 8 or 9 month difference in age. I'm asking this because I know chickens are extremely aggressive towards new chickens. Well, most of the time. Are ducks the same way? I don't see that happening but I thought I would ask anyway.