I have read about animals acting crazy before disastrous events, like the big New Madrid earthquake in 1805 (I should check the date). Lewis and Clark wrote about that. And, of course, old Native American tales tell about how strangely the animals behaved at that time.
I'm sure there are many other such incidents. Maybe some of our historians can fill us in on this.
1811-1812 (*cough*).
The interesting thing about the New Madrid quake is that is often given as a period of time rather than as a specific point in time. There were many violent earthquakes during this period, not just one. When you consider that the geological explanation for that event was the North American continent ripping itself into two pieces, it seems more reasonable.