We had a swarm of locusts once when I was growing up on the high plains of Texas. Not the locusts most people are used to. These looked like giant grasshoppers--I'm talking the length of an average ink pen and as big around as a carrot, with bright colors of red and green on their bodies. There were billions of them in the air, on the ground, everywhere. You couldn't walk through them without being bombarded, and it actually hurt when they hit you. We drove through them in our pickup with the windshield wipers on high, and even that couldn't keep them cleared from the windshield long enough to drive any faster than a crawl. You could hear the crunch of them beneath the tires. It was surreal.
It took them a day to strip every bit of green from every living plant around. Then they left, leaving nothing but bare earth and hundreds of dead locust bodies.
Only saw it once in my life. That was enough.
There is a similar, more widespread report on historynet.com under "1874: The Year of the Locust". I know exactly how those people felt.