My parrot has a specific way of thanking. Whenever i or someone else hands him a treat of some kind ( a fruit, biscuit etc. ) he makes a noise, like a cough, which he never uses the rest of the time. He makes that sound EVERY time , immediatly after he gets the treat ( but he makes a completely different sound after i pet him ). Has anyone else observed a similiar behaviour? Pay attention to what your grey says after you give him something.