Jessie Fullenkamp still remembers the day in 2004 when she walked out of a building in Cincinnati, US and found her car - and all the other cars in the parking lot - covered in cicadas. Then a college student, she made a resolution. "I decided at that time: I don't know where I'll be living in the world, but I want to come back for this with a little bit more intention," said Fullenkamp, a social-work researcher. Now 36 and living in Detroit, she started talking to her friends in Cincinnati about a "cicada-cation" six months ago. "They thought I was joking at first," she said.