okay, Muse, here's your response, equally tedious i'm sure to readers without cats. in fact sometimes i even bore myself with my own cat stories, but there it is. . . so the thing with my cat is that not only does she know the rattling sound of the bag of junk food, she knows the sound of which chip i'm going to share with her. it all started with smart-food popcorn, the mere whiff of which could cause her to stick her big paws deep into the bag given half a chance which we never gave her of course. however, when we would give her a piece, we didn't want her to choke on the hulls so we would customize the piece by biting off the hull and giving her the rest of it. something about that careful surgical sound was readily identifiable so that now (although smart-food never enters the house anymore due to my absolute inability to not eat the entire bag in a sitting -- what drugs are in that cheese coating?)any time i make a similar noise with a tortilla chip or other crunchy item she figures it's hers. i know just how pathetic and bizarre this must sound to non-cat owners, and in fact i'd like to blame my sister, who helped me raise the cat with bad habits ("doing the doberman" was one of the tricks she taught the cat) and then insisted i take the cat with me when i moved out of the apartment we shared. plus my sister never ever visits the mudcat so i can more easily make her the scapegoat.