Motivation is both vexingly and wonderfully complicated!
It seems the final point here is 'We don't know why [[contra-freeloading]] exist! Not a very exciting explanation. I think I'd rather take the [[@Inglis.etal1997FreeFoodEarnedFoodReview]] account: the explanation of the phenomenon is [[exploration]]-motivated behavior, even if the explicit motivation is not represented by the animal in terms of exploration. What they're doing is enriching (and maintaining the richness of) their map of their environment. That must be the function, and then the explicit motivation can be something else.