[4zenuff]

Yes, my pup does this too. She's 16 weeks tomorrow. It doesn't matter what it is! She even plays with her food...one kibble at a time. It sometimes takes her forever to eat. She has to grab and run, then let it go and pounce it. She doesn't do it with her food as often as she did when she first came to us.
But everything else (grass, dirt, twigs) is fair game!