‘They’re going to be everywhere.’ Ann Arbor preparing for massive swarms of cicadas Updated 11:20 AM; Today 11:12 AM Brood X cicadas, like this one from 2004, will emerge in the billions in 2021 for the first time in 17 years. (Photo by Paul Savage | The Times of Trenton) Facebook Share ANN ARBOR, MI — Billions of Brood X cicadas living underground for the past 17 years are about to emerge, and Ann Arbor is taking some precautions as it prepares for massive swarms of the red-eyed bugs. Large parts of the Midwest and eastern United States are expected to experience the 17-year cicada emergence over several weeks in May and June, and Ann Arbor’s forestry department is expecting the insects to put on quite a show as they take to the trees in Tree Town.