Why Billions of Cicadas Are About to Emerge After 17 years

For the first time in 17 years, one of the largest broods of cicadas is about to swarm the Midwestern and Northeastern United States—here’s what you need to know. » Subscribe to Seeker! » Watch more Elements! » Visit our shop at Cicadas species fall into two broad groups: annual that can be seen every year, and periodical that emerge in cycles that last 13 or 17 years. That’s not to say a certain species can only be spotted every 13 or 17 years, because the same species can have multiple broods that emerge in different years across different geographical regions. There are 15 brood cycles and the one set to emerge this year is one of the largest: brood X. Billions will climb out of their little underground burrows and shriek their little hearts out when it’s warm enough to do so. Before emerging, periodical cicadas spend all those years underground in the nymph stage of their life cycle, dri