It really IS nothing to worry about. Vanilla is 18 months old and is an extremely happy and calm dog. When we first got her every day she would have what we called "crazy bunny runs". She would start running from my front door all around the house super fast with intense speed. It was so funny cause she looked like a bunny.She'd get a toy and would attack it. If she would try to get out pants we would say NO and she would stop. This is all normal puppy behaviour.