All three of my cats come running when they hear the electric can opener. This is from the days before their canned food had pop-tops--years ago...but they haven't forgotten the sound of the can opener. When I'm cooking dinner and they are off resting quietly somewhere, instead of disturbing them, I dig for the old manual can opener!! Have they got me trained? One of my boys joins us for dinner every evening...I started telling him he wasn't cute enough yet for a treat and he started rolling onto his back, paws in the air, looking awful darn cute....now I just have to say - You don't look cute enough yet - and he rolls onto his back. 'Course he always gets his treat!