Photo by: Shutterstock

Shutterstock

If Cicadas Come Out Once Every 17 Years, Why Do You See Them Every Summer?

By: Discovery

These mysterious insects have one of the strangest life cycles in the natural world.

August 01, 2019

In certain parts of North America, you can expect it every summer: the constant, droning buzz of cicadas. But if you hear it every summer, how is it possible that cicadas only come out every 13 years?

One Of These Broods Is Not Like The Other

The periodical variety of the winged insects known as cicadas spend most of their lives underground, sucking sap from tree roots as they slowly grow into adulthood. Finally, after either 13 or 17 years, depending on the breed, the cicadas finish counting the annual blooming of the trees, wait for the soil to warm, and tunnel straight up out of the ground.

But if periodical cicadas only emerge every 13 or 17 years, why do we see them every year? It's because they don't all emerge at once. Cicadas are grouped into roughly 15 broods: 12 broods of 17-year cicadas and three broods of 13-year cicadas. Each of these broods emerge in different years, so residents in cicada regions rarely spend a summer without them. On top of that, many other species of cicada aren't periodical but annual, meaning they emerge every year.

This article first appeared on Curiosity.com.

Next Up

Silver-backed Chevrotain Photographed for the First Time in the Wild!

First-ever photos and footage of the silver-backed chevrotain, tiny deer-like creatures, have been photographed in Vietnam after an intense search.

What’s Baking in Alaska?

A trending new addition to travel bucket lists around the world is frigid-yet-beautiful Alaska. The poles, the dancing lights, and the winter wonderlands have always attracted the extreme traveler - but this time, there is more than the magical draw of the north that is inviting people up towards the corners of the globe: climate change.

Two Little Penguin Chicks are Hatched at Bronx Zoo

One-month-old chicks join zoo's growing little penguin colony

What You Need to Know About the Amazon Rainforest Fires and How You Can Help

The Amazon rainforest is burning at a record rate. Here is what you need to know.

These 7 Traits Make You Irresistible to Mosquitoes

Learn about mosquitoes at Discovery.com

70% Of Earth's Fresh Water Is Frozen

Our freshwater is locked up in the Antarctic Ice Sheet.

The Hallucinogenic Angel's Trumpet Plant Is Beautiful and Deadly

This beautiful, bell-shaped flower ready to send you straight to the hospital.

Big Sur Condors, A Conservation Comeback Story

Condors once ranged from Baja California all the way to British Columbia. But, in 1987, the last wild California condor was taken into captivity in order to preserve the species. Now, thanks to a breeding program in central California, the condors are finally returning to their natural habitat in Big Sur.

Living with People and Elephants in the Serengeti

There has been a lot of not-so-great elephant news out of Africa in the last couple of decades. Between 2006 and 2015, an estimated 100,000 elephants disappeared across the continent. However, the story of the Serengeti is slightly different to other national parks in Africa. Here's some insight as to why.

These Bee Chicas Are Colorado’s Local Heroes

Last year, US beekeepers lost almost 40% of their bee colonies. Four women banded together to help the bee population flourish in Colorado.