I heard this topic addressed by a dog specialist on Animal planet. He said it goes back to the "ancient dog ancestors" that would grab a piece of the kill and go off to a secluded place to eat it so that it would not be eaten or snatched by other pack members. I'm not sure that Max or Maggie have read that article.....but they do the same thing.
Maggie will snatch greenies, chews, etc right out of poor little passive Max's mouth and Maggies cheeks will be absolutely stuffed full. Then she searches all over the place to find hiding spots for them. Sometimes she "hides" them in plain view but will pull up imaginary dirt over them. Hysterical!!!
They keep my life interesting. God bless them>
Max and Maggie's Mom