My gerbil recognizes the sound of her cage opening, she runs and hides under cover from scary hands scooping her up

My duck, scruffy, recognizes the sound of the door opening. Whenever the door opens he gets up from what he is doing a checks out who comes out from the door. He is wating for me, of course! He might be wanting food, playtime, or just a great big hug! He also recognizes his name and my voice (Well I think he does lol) and he comes running with Joy and his tail happily wagging (reminds you of a puppy!) when I call his name.