weird scratching behavior

I have been owned by cats since I was 5 years old and thought I pretty much had them figured out til we got our newest addition a year ago. Her father was pure burmese and her mother 1/2 siamese which I suppose makes her 75% tonkinese. She has the tonk markings and exhibits all the tonkinese behaviors. One of the strangest things she does is after she finishes eating she scratches around her food bowl in a circle like she is trying to bury it . Only there is nothing there to scratch or move. Sometimes she will steal a "snack " from the dog's food bowl which is up against the refrigerator and when she is done she will scratch all the way around it and then reach up and scratch the side of the fridge. It is classic litter box behavior but why does she do this to her food ?