A black cloud on the horizon races towards your homestead.

In the life of an Oklahoma farmer during the Dust Bowl, this was not an unusual sight. You’d herd what livestock remained into the barn and gather your family inside your house, stuffing wet sheets into the cracks to keep out the incoming dust. Then, as the wind rattled the door and dirt scratched against the windows, you’d wait.

But this cloud is different. It doesn’t roll like a duster. It’s fast and erratic, not moving with the wind. Sunlight slices right through it, flickering throughout its depths.

And it buzzes.

Because it’s not dust. It’s a massive swarm of grasshoppers.

During the 1930’s, the drought and dust didn’t just push the human inhabitants of the southern Plains to brink of desperation. It threw off the balance of the natural world too, resulting in plagues of insects that neared biblical proportion.

Dust Bowl survivors recall mounds of centipedes scurrying across the floor, hiding in drapes, and scratching inside the walls as they built their nests. Tarantulas ran rampant, many bigger than your fist. And children, terrified by the stories they’d heard about death from a single bite, refused to get into bed without first scanning for black widows.

But the grasshoppers. The grasshoppers were even worse.

Although small, a single grasshopper can consume half its body weight in a single day. And as the drought worsened and food became scarce, the insects became bolder, using their sheer numbers to ensure survival. The swarm would move over fledgling farms, covering the newly emerged wheat like a blanket and decimating what little vegetation remained. When that was exhausted, the horde would move on to tree bark and the wooden handles of tools. Some were even known to attack people, chewing holes through their clothing. As President Franklin D. Roosevelt put it during one of his fireside chats, “What the sun left, the grasshoppers took.”

And it wasn’t just the farms affected. So many grasshoppers covered area railroad tracks in Colorado, the trains were unable to move. Squishing such a large number of bugs created a slimy, soupy mess on the rails, preventing the train’s wheels from gaining friction and moving forward. In the same way, drivers reported roads as slick as ice from thousands of crushed insects.

It seemed the same conditions that withered the land and eradicated thousands of animals actually created an environment in which certain insects, especially grasshoppers, thrived. How was that possible?

It was a combination of factors, really. In normal conditions, eggs would be laid, but cooler, wetter weather would kill off at least half. During the hot, dry months of the Dust Bowl, more eggs were allowed to hatch. In addition, the wetter months would produce a fungus on area plants that would poison another significant portion of the population. Without the rain, no fungus would grow, and no plants were around to hold the spores.

Another contributing factor was the lack of predators. The drought killed off a large part of the local bird and snake population. A kink in this natural system of checks and balances allowed the grasshoppers to survive and multiple without limits.

That isn’t to say that another predator–man–gave up without a fight. The situation got so desperate the National Guard was called in to manage the pests. They tried several methods–including crushing them under tractor wheels and burning infected fields with flame-throwers–before finally discovering a solution. A mixture of sawdust, molasses, bran, and arsenic was sprayed from the air and distributed by seeding machines, finally killing the scourge. It was a much-needed victory against nature in a decade marked by one-sided battles. Or was it?

The poison was so effective, many residents were sickened during the application. Even more disheartening, it not only killed the grasshoppers but also the crops on which it was sprayed. Farmers who clung to the precious, little crops that were meant to feed struggling families or create a meager livelihood now had to make a choice to make: grasshoppers or poison?

It was just one more impossible, unwinnable decision faced by those who remained in the Great Plains during the worst man-made natural disaster of the twentieth century.