I have 2 ducks that are 5 1/2 weeks old, and 2 little ducklings that are 1 1/2 weeks. Even just a month apart in age there is a significant difference and sizes, and although I think it's out of curiousity rather than trying to harm them, our older ones will sometimes try to get too close and peck at them at times. As of now we are slowly letting them all interact, mostly just letting them look at each other and get used to each other (while keeping a bit of distance), and always with our supervision. Is there anything else I can do to make this transition easier? A good age the little ones will be big enough to interact with our older ones?