Hi everyone! Alfy my yc Amazon is 4 and half years old. He has just started to quack like a duck! It began when my husband stroked his back but now he does it in or out his cage. He starts with a 'twitching' motion. It's very cute and he appears very happy but can anyone tell me why he does this? He is an extremely healthy bird, full feathers and good diet etc. Thankyou. Cate and Simon Smith, Nottingham, UK