They're no giant murder hornets, but they do make a racket. Millions upon millions of cicadas are due to surface this year after 17 years in the ground, CNN reports. People in Southwest Virginia, parts of North Carolina and West Virginia will witness the event this year, per Virginia Tech. They're harmless to humans, though cicadas pose a danger to crops and plants because they leave their eggs in branches or vines, which can then wither and split. A small tree can die if enough cicadas implant eggs in it. Owners of vineyards and orchards will want to keep an eye on the infestation, the school said.
Otherwise, the main issue is noise. An acre of land could host 1.5 million cicadas, per NBC, generating what the school said might sound like "a field of out-of-tune car radios." That's not what it sounds like to cicadas: It's the male's mating call. Periodical cicadas follow a 13- or 17-year cycle, and it's not known why. One theory is that it keeps them from being on the same schedule as predators. A Virginia Tech professor suggests we savor rare experience. "If you don’t have fruit trees or grapevines to protect," Doug Pfeiffer said, "you can enjoy this phenomenon while it lasts." But then, he's an entomologist. On his blog, Pfeiffer also analyzes the giant hornet situation. (More cicadas stories.)