Heh, hard to imagine what a dog can smell. My wife started bringing treats from a particular restaurant. So when she would come home from that particular restaurant our normally polite dog would run and check her bag.

We thought it was the bag she smelled... until she left the bag outside in the car. Our dog smelled her, asked to be let out into the garage, asked to be let out into the driveway, then asked to be let into the car, and then nosed her bag.

We were amused.