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Wet weather may not be only factor driving Las Vegas grasshopper invasion

Las Vegas doctor says serotonin may be to blame
Posted at 12:09 AM, Jul 29, 2019
and last updated 2019-07-29 08:57:44-04

LAS VEGAS (KTNV) — Las Vegas is ground zero for a grasshopper invasion that's brought thousands of the flying insects to the valley. Nevada's state entomologist says the invasion is the result of a wetter than normal winter and spring, but the wet weather may only be part of the story.

Dr. Daliah Wachs, a Las Vegas family physician and nationally-syndicated radio host, believes a powerful chemical is partly to blame for making these grasshoppers so happy and eager to reproduce.

"Las Vegas is one of the happiest places on earth and it’s one of the most social places on earth and the reason why people have such a good time when they come to Vegas is, I think, because of the serotonin boost," said Dr. Daliah.

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Serotonin, also known as the "happy chemical," is a neurotransmitter naturally produced by people. Dr. Daliah says it's capable of regulating mood, social behavior, appetite, sleep, and sexual desire in humans and grasshoppers too. She points to a 2009 study from Oxford and Cambridge Universities that found serotonin levels were three times higher in grasshoppers who were swarming as opposed to solitary, less sociable ones.

RELATED STORY: Grasshoppers go viral after swarming Las Vegas Strip, entomologist warns predators could follow

"Grasshoppers may have a similar response as humans when it comes to the happy hormone. Serotonin makes a solitary grasshopper become more gregarious and more social. It really mimics and parallels what humans do," said Dr. Daliah.

The same study found grasshoppers get stimulation through their hind legs, especially when crawling over each other during a grasshopper gathering.

"There’s a snowball effect where the closer the grasshoppers are together, the higher the serotonin becomes. So, what ends up happening is, one feeds on another, which feeds on another, which is why we saw it happen so exponentially," said Dr. Daliah.

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So, when you see grasshoppers swarming the Las Vegas strip, Dr. Daliah says they're probably high on serotonin and seeking many of the same things people are.

"They want to party and they want to see J-Lo and Christina Aguilera and everybody else, but they’re having a happy time right now. They’re making babies and they’re loving life right now," joked Dr. Daliah.

Just remember, the grasshoppers are harmless to humans and Nevada's state entomologist only expects them to be here for a couple more weeks at the most.

EARLIER STORY: Why are there so many grasshoppers in the Las Vegas valley? Nevada entomologist explains