Why did 45 million grasshoppers swarm Las Vegas in 2019? Bright lights weren't the only factor. Dustin Barnes, USA TODAY Replay Video In the summer of 2019, the bright lights of Las Vegas drew in more than just tourists looking to gamble and party. The glow of the famed strip also was responsible for summoning some 45 million grasshoppers, according to a recent study. "It turns out Las Vegas gets fewer people to come gamble in the course of a year than the grasshoppers in the sky on that single night," said Elske Tielens, a researcher at the University of Oklahoma and one of the study's authors.