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The cicadas in Illinois are here: Five facts to know

Cicadas have arrived in suburban Chicago
Cicadas have arrived in suburban Chicago 02:24

The countdown is over.

Cicadas have started popping out of the soil in the Chicago area and across Illinois.  

Here are some answers to common questions.

Watch Live: Cicada Cam! Tuesday, May 21st | CBS News Chicag by CBS Chicago on YouTube

Do people eat cicadas?

For the first time in 17 years, trillions of periodical cicadas are here— and as you may have heard, you can indeed eat them.

It just so happens that CBS 2's on-air talent roster members have eaten cicadas on television – more than once.

2024 Illinois cicada map

There are two groups of periodical cicadas — those that emerge every 13 years and those that emerge every 17 years. For most of their lives, cicadas live underground and emerge once the soil reaches 64 degrees. 

Why are cicadas so loud?

As explained in Science Daily, cicadas make their sounds with a corrugated exoskeletal structure in the thorax called a tymbal. The tymbal is an organ with the specific purpose of producing sound, a category it shares like a rattlesnake's rattle – which some say sounds not unlike a cicada.

But while rattlesnakes rattle their tails as a warning when threatened, cicadas have no such ominous intent. Only the males make the noise, calling out to attract a female mate.

Cicadas undergo some fairly complex contortions to make their tymbals produce such sounds. Derke Hughes of the Naval Undersea Warfare Center told Science Daily that if a human body were like that of a cicada, it "would have a thick set of muscles on either side of your torso that would allow you to cave in your chest so far that all your ribs would buckle inward one at a time into a deformed position. Releasing the muscle would allow your ribs to snap back to their regular shape, and then pulling the muscle again would repeat this."

Cicadas are very loud indeed. Extension entomologist P.J. Liesch of the University of Wisconsin-Madison told CBS 58 in Milwaukee that a grove of trees with a bunch of singing and screeching cicadas could reach 70 to 80 decibels – a similar volume to a vacuum cleaner.  

How long do cicadas live?

Cicadas spend the vast majority of their lives underground and emerge at the end of the 13—or 17-year cycle. When they emerge, their job is to reproduce.

To attract mates, male cicadas start buzzing loudly — which is why a loud droning sound accompanies the presence of cicadas. According to Ken Johnson, at the University of Illinois, they begin this process about four to five days after they emerge.

Matthew Kasson, an associate professor of mycology and forest pathology at West Virginia University, said the females flick their wings to signal to the males that they want to mate.

Johnson said females can lay 500 to 600 eggs. They lay their eggs in woody plants, using their ovipositor, or egg-laying organ, to inject about 10-20 eggs into branches.

The eggs hatch about six weeks after they're laid, and the babies fall to the ground, eventually digging themselves into the soil, where they will remain for 13 or 17 years.

Their parents, however, die shortly after the mating process, lasting only about a month above ground. 

What animals eat cicadas?

How do creepy crawlers mix with furry friends, and what do pet owners need to know about the swarms expected everywhere?

"They are not toxic to pets. They won't sting or bite your pet," said Dr. Cynthia Gonzalez of Family Pet Animal Hospital in the Lincoln Park neighborhood. "The only issue that would present for your pet is if they were to ingest a large amount of them, or if they're a smaller dog if they ate a small piece of the exoskeleton – sometimes that can really irritate their GI tract."   

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