Our 2 new Cayugas are in a pen next to a couple of our other ducks. The Cayugas are female and next to them is a female and her 9 week old son. The Cayugas only arrived yesterday. I noticed today our female in the other pen and one of the new girls are bobbing their heads at eat other and quacking super loudly. The feathers on their necks seemed to be slightly raised. Are they showing aggression towards each other? We had 2 other ducks in this pen up until yesterday and I didn't see any of this type of behavior with them. I'm not sure if I'm just interpreting their loud carrying on and head bobbing as dislike for each other or not!