Rat Attack

It is 1959: in this remote corner of India, freshly dug graves, too numerous to count, speak of an unfathomable horror. In the forests, men desperately search for food, as famine stalks the countryside. Mothers dig up roots to fill bellies. Some hike hundreds of miles to find rice for their starving children.
But it is the cause of this calamity that totally defies explanation. It is a natural disaster unlike any other, one that comes, not on the wind, like a cyclone or drought, but on four legs and by the millions. It is a plague of rats.
Now, exactly 48 years later, an almost identical plague is sweeping the country again. Across the region, colossal armies of rats rampage through the countryside, obliterating rice crops, leaving nothing.
Local tradition says the rats pour out of the bamboo trees, that the forest gives rise to the plague. But what is the real cause?
Scientists know little more about this onslaught than they did almost half a century ago. That’s about to change.
Biologists are racing to the scene of an event so steeped in myth, they don’t know what they’ll find.
And they don’t have much time to figure it out.
Is there any way to avoid it?
It’s a Rat Attack, right now, on this NOVA/National Geographic Special.