Looking for some advise with my Indian Runner ducks. Currently I have 3 females and 1 male. They are 2 1/2 years old and were raised together. They have always lived together and have always gotten along very well. Just recently, (1week) they have started to pick on one duck. Originally the male was not involved but now is just as bad. They have pulled off all the feathers in one spot on the back of the duck. One other duck is missing some feathers, but not to the same extent. It is beginning to look quite ruffled and unkempt. I have brought it into the garage in fear that they may eventually kill it. I have actually seen them pin it to the ground and gang up on it. It is feeling a little thin, and wonder if they were not letting it eat. It seems as if when they start to fight they are almost in a complete frenzy. They get squabbling and make a huge ruckus, and then start pecking at it. They also seem to almost wrap their necks around each other. Any suggestions as to what might be going on? I have never seen this behavior in them before. Any advise would be greatly appreciated .