Seems like i'm always asking questions here at BYC But thats because it's the best site on the web to get advice from great people who have hands on experience in what you need to know. OKay i have had 2 pairs of grey calls together since i got them 3 months ago thier age is ?(anybody know how to tell the age of a duck) They were also together at the breeders house where i bought them. Well i have moved them to a larger pen and now one of the males is chasing the other male and biting him in the rear. The biter stands with the 2 females while the other stands at a distance not wanting to be bitten. They had been molting but are now almost feathered back with their gorgeous little green heads. Whats up with the tail biting and why did it start? Is it time to move them into separate pairs?