Tens of billions of insects are set to appear across the US over the next few weeks in an ultra-rare synchronised 'emergence' - the first of its kind in over 200 years.
Two broods of infamously loud cicadas are due to start popping up from underground across the American Midwest and Southeast from the beginning of May to undertake a mass mating ritual.
Some experts have warned that over one trillion of the insects could cover areas where the two broods coexist - but, fortunately, the species is harmless to humans.
For insect experts, the emergence of both sets of cicadas is truly a once-in-a-lifetime opportunity; the last time this happened was 221 years ago in 1803.
The cicadas are set to emerge in the same place, with the broods' habitats overlapping in parts of Illinois and Iowa
Getty/Cicada Safari
Jim Louderman, a collections assistant in the insect division at the Field Museum in Chicago, told NBC: "It's something that no one alive today has ever seen and no one alive today will ever see again... For entomologists, it’s a really, really huge deal."
The two groups of bugs are known as Brood XIII and Brood XIX periodical cicadas; the former emerges once every 17 years, while the latter once every 13.
When the soil temperature around 20cm underground passes 18C, the cicadas will come out in a frenzy of singing and mating before dying - which Dr Jonathan Larson, an extension entomologist and assistant professor at the University of Kentucky, told CNN would be like "the most macabre Mardi Gras that you've ever seen".
It's not just the fact that the two groups are set to emerge at the same time which has sparked excitement in the scientific community - they'll come up in the same place, with the broods' habitats overlapping in parts of Illinois and Iowa.
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Jim Louderman said the synchronised emergence would sound "like 1,000 chainsaws going off"
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Daniel Young, an entomology professor at the University of Wisconsin-Madison and the director of the school’s insect research collection, said: "Not many people in human history are going to be in a place where they can witness that.
"A lot of people may find it very unpalatable, but it's a pretty amazing thing."
Young and Louderman are planning to track the historic emergences with their respective institutions, and both have expressed their desire for the public to get involved, with the latter drawing parallels between the event and April 8's solar eclipse.
Louderman added that "there was a periodic cicada emergence when I was eight, and that got me hooked on insects and entomology", and said he hoped young people may take similar inspiration from this year's event.
The cicadas will die within days of emerging, with their skins "literally paving the sidewalks and streets"
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He detailed what people should expect when the cicadas arrive, saying: "There's just so many of them that the noise is almost deafening... It's like 1,000 chainsaws going off, and they’re all being used at the same time.
"They literally pave the sidewalks and streets - it's just crazy... Some people get kind of freaked out by it."
Dr Larson added: "We're talking about an absolute oddity of nature... one of America's coolest insects.
"I really hope that people will appreciate this for what it is: this unique natural phenomenon that you don’t get anywhere else. It's beautiful."
