We have a 15 week old Grey-who we have had since he was 14 days. he has suddenly started attacking our 14 and 12 year old. they have been very involved in his raising, formula feeding him, etc.... suddenly he has turned on them not sure why. he will lunge and screech at them, and bite as hard and fierce as he can. yet when the 14 year old feeds him.. he is lovable. i notice it nore when I am in teh room, so i think he is bonding more with me. how do i stop this behavior, before it gets out of hand