Here's an experiment you can try on YOUR own, as long as you have peanuts in the shell and a good population of squirrels.
Place a small pile of unmodified peanuts in one location; put just shells in another (a good distance away, within sight of the squirrel but requiring someTRAVEL ); in the third, put a pile of shelled peanuts (from those shells you left in pile two).
Describe and analyze the foraging activity of the squirrels.