Back in the day there was a series of books written by a woman named Laura Ingels Wilder. They are commonly called the "Little House On The Prairie" series. (one of the books took place in a town called Walnut Grove which is only a few miles from me)
In one of her books she talks about a grasshopper invasion. She says the chewing noise the millions of grass hoppers made would drive people mad.
One day the grass hoppers started marching and all together marched the same direction. After doing this for a while the took to the air and they were so thick that they blocked out the sun. After they were gone not one green thing was left in their wake.
We are all lucky to live in this era when insects are not as bad as what they once were.