It turns out this mass insect incident was the meeting of two events, Tielens said. "One side is the bright dome of light over Vegas, the brightest city in the U.S. But on the side, you need this really large population of grasshoppers." And that booming population was the result of a wetter winter and spring which had created more vegetation for the grasshoppers to feed, she added. Though swarms of insects may bring biblical themes to mind, these grasshoppers didn't decimate the area's vegetation. They didn't bite and torture Nevadans or wildlife. However, this massive swarm did create a nuisance for tourists and residents, scaring them from going out or just scaring them in general, Tielens said. And it's likely this gathering of grasshoppers made their natural predators very happy. Birds in the area, for example, had more food which can translate to healthier eggs, better nest survival rates and therefore more chicks the following year.