It has started.

A grizzly bear at the Minnesota Zoo grabbed a huge rock and hit it against a glass window until it shattered. The zoo's Director of Animal Collections, Tony Fisher, chalked it up to a little bear playfulness along with the fact that "rocks and glass don't get along." But this could also be the first in the inevitable string of instances of animals fighting back against their oppressors (humans, and I include myself in that group) until they're the ones in charge. Fisher also told USA Today:

Sources: h/t Gawker