Is bopping ever justified?

A rabbit finds itself hopping through the forest. In order to amuse himself, he begins scooping up the field mice that he finds along the way, and bops them on the head. Is this a right action? Is it justified?

But consider the following alterations to the example: The rabbit is hopping through the forest. In order to amuse himself, he picks up the occasional field mouse. The mouse, being a rather vicious animal, bites the rabbit on the paw. So, in retaliation (and perhaps for his own safety), the rabbit bops the field mouse on the head. Is this now a right action? Is the action justified?

Let us consider yet another possibility: Unbeknownst to anyone (including rabbits and non-rabbits), the field mice have been gathering to plot a massive attack against the rabbits. While field mice are considerably smaller than rabbits, one at a time, they are helpless against the enormous rabbit. However, they, at some point, realized that if they were to all join together, their masses could beat the rabbits rather easily. An agent, call him Bunny Foo-Foo, does not know of the master plan of the field mice. As he hops through the forest, as he usually does, he begins picking up the field mice and bopping them on the head. The number of field mice that he bops before his actions are stopped by the sovereign (call her the Blue Fairy if you will), is sufficient to hold of the attack of the mice (at least until they produce more mice). As Bunny Foo-Foo has now single-handedly saved the rabbits from complete and total destruction, it seems he has now done a good thing. Is the action now right? Even if Bunny Foo-Foo was not privilege to this knowledge? Why or why not?

Discuss.