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:
He plays a lot. He plays with everything, you know, sticks and mud and fish and you know, he stays busy out there all the time in the water...
Sounds like he's testing out the various tools at his disposal.
The zoo now plans to bolt down moveable objects and replace the shattered glass. But the bears will never go back to the way things were before. And we can't either.