I have 7 ducklings that are 6 weeks old females. Just yesterday 6 of them have all started to run away from 1 of the ducks. They won't let her near them for anything and sometimes they chase her away if she happens to be close. They have always all gotten along well as a group and the one they are isolating is a nice one. Do they sense something that is causing them to isolate her? Could she be sick? Did she do something to offend them all as a group? These are my first ducks and I am worried about her. I don't see any signs of illness, but I don't know what else it could be? Should I attempt to reunite them all or just let them work it out? Thanks for any advice!