Just had the ducklings out for a swim. It seems the 2 older (3 weeks) ducks are pecking each others tail feathers. Comparing them to the 2 week olds whose tail feathers are coming in full, the older ducks tail feathers have been basically stripped clean, just the shafts are there. ACK!!! What do I do? Why are they doing this? The two older ducks have been together since they were 1 week old. The rouen is twice the mallards size, but until this, they have been the best buddies. I moved them into the bathtub so they would have more room and then this started. How do I stop it and will they grow back? HELP!