@futurebird some time ago I heard a podcast episode on army worms, the fall army worm and the true army worm, two different kinds of caterpillars which feed on grass and reproduce (as moths) in huge numbers thanks to golf courses and suburban lawns. Having spent nearly all my life west of the Rockies, I've never seen them, but I heard they're a "menace"* in the southeast usa, and in bad years can spread as far north as New York and Toronto. (*I hate lawns and root for the caterpillars.)