First. while eating she drops some of her food on the floor and/or stuffs in into her chair for later.
Second, she scavenges the kitchen floor multiple times per day, picking up and eating whatever she can find, no matter how old it is.
Third, when I'm in the kitchen she hovers around me so that when I open the fridge to get something out, she weasles her way around me in search of something to retrieve.
Fourth, and most disgusting, is taking food from the trash can. I can't seem to keep her out of it.
And here is evidence:
Licking her bowl clean:
Searching the fridge:
Retrieving her loot:
This mustard container WAS in the trash: