Conditioning goes both ways, people. If you train a pet, your pet is training you just as much. Manipulation is a tricky thing, and you never realize you’re a victim until it’s far too late. Gidgit the Guinea Pig had taught her owner that whenever the fridge was open, it was chow time for Gidgit.
The guinea pig knew the sound of the refrigerator door opening. No matter where the furball was or if it was fast asleep, if the fridge door made a noise, it was squeal in delight and demand food. The OP would further explain that it got to the point where she was unconsciously bringing lettuce to the guinea pig whenever she went to the fridge.