Billions of Cicadas Have Emerged Across the U.S. Could Their Waste Be a Concern?

Here’s a question you might want to skip while enjoying a meal: Which animal has the fastest urine stream in the world? Is it the elephant? The lion? Perhaps the horse?

Interestingly, as revealed in a journal study Proceedings of the National Academy of Sciences, one of the unexpected contenders is the CICADA. Researchers, likely equipped with goggles, found that these tiny insects can shoot their pee at speeds of up to 3 meters per second.

While that’s quite astonishing, billions—possibly trillions—of cicadas emerged in the US in 2017, possibly making you reconsider your summer plans.

So, should you be hiding away until the cicada frenzy subsides? Experts say that it might be wise, but it may not be for the reasons you think…

What are Cicadas and why are they headed our way?

“Cicadas are remarkable insects known for their unique life cycle and distinctive sounds,” says Dr. Elio Charita, one of the primary researchers on their urination studies at BBC Science Focus. “These sap-sucking insects belong to the order Hemiptera and can be found in temperate and tropical regions worldwide.”

Cicadas can grow quite large and are, indeed, very noisy. Their calls can reach volumes comparable to a chainsaw.

“One intriguing aspect of cicadas is their long juvenile phase, during which they spend several years underground feeding on plant roots. Depending on the species, this phase can last from a few years to 17,” Charita continues.

This year, the US will witness the significant emergence of Brood XIV, the most extensive group of regular cicada broods, as noted by the University of Connecticut.

After spending over a decade underground, these fascinating insects will appear en masse for a brief but enthusiastic mating season. Expect to see them across much of the eastern US, including states like Georgia, Kentucky, Indiana, Massachusetts, North Carolina, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia.

If their activity persists until late June, prepare for their numbers to swell at any moment.

For more on the cicada life cycle, be sure to check out our detailed article.

Is it time to prepare for a pee-pocalypse?

Before stocking up on canned goods and toilet paper this summer, Dr. Jonathan Larson, an entomologist at the University of Kentucky, tells BBC Science Focus that there’s really not much to worry about.

“For many, the thought of a swarm of six-legged bugs might recall sci-fi movies, but in reality, it’s more of a spectacular, almost Mardi Gras-like experience.”

Though large, cicadas pose no threat to humans, animals, or crops.

Larson also points out that compared to the Peruvian cicada species, which emerges annually, US cicadas are expected to feed and urinate less during their short lifespan.

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“In our studies, we find that these US species feed far less as adults compared to some others. When they emerge, their primary focus is finding a mate,” Larson explains.

Nevertheless, they still spend time feeding and urinating. Charita notes that cicadas have been seen urinating jets, even captured on camera.

Another upside (if you can call it that) is that cicada urine isn’t like that of larger animals. As mentioned, cicadas primarily excrete sap from trees, which is the same substance that forms the basis of maple syrup. Thus, what drips down is a sweet, watery substance known as “honeydew.”

Although it has a delightful name, I wouldn’t recommend tasting cicada pee this summer, but at least if it lands on you during a walk, it won’t be unpleasant.

As Larson says, “You can leave your umbrellas at home; these cicadas aren’t a big problem.” Phew.

“Watch your step.”

So, while cicada pee is remarkably fast, it’s not a major concern. According to Larson, the real issue arises when they die, not when they urinate.

“They tend to die en masse, creating piles of carcasses, which can lead to slippery sidewalks. I think that’s a more significant issue to worry about,” Larson says.

How significant could this be? Reports from 1990 indicated that people used snow shovels to clear sidewalks of dead cicadas.

What’s even worse is that when billions of these bugs die simultaneously, it leaves behind a nasty odor. Some have described the stench as reminiscent of rotten nuts.

On the bright side, this process enriches the soil with nutrients, such as nitrogen. Although the smell may be unpleasant, these insects are beneficial to the ecosystem.

How Cicada Pee Could Inspire Future Robots

According to Charita, the fact that cicadas can generate such powerful urine jets is surprising for two reasons.

1. Most insects don’t exhibit this behavior because producing jets like larger animals demands a significant amount of energy. Typically, insects excrete urine in droplets. And since cicadas primarily consume sap with low nutritional content, this adds another layer of energy efficiency issues.
2. Moreover, earlier studies suggested that creatures weighing less than a kilogram are too small to generate such powerful jets, making cicadas’ ability unexpected.

Understanding this phenomenon is crucial for a variety of reasons. Given that cicada populations can number in the trillions, their role in environmental nitrogen cycling may be significant.

“We still do not fully grasp the ecological effects of cicada excretion on surrounding flora and fauna, especially for the seasonal species,” Charita notes.

When feeding, cicadas consume up to 300 times their body weight in sap daily, and all that sap has to go somewhere.

The research team also considers broader applications for this work. Insights gained could lead to advancements in small robotic jets, nozzles, and various applications in additive manufacturing and drug delivery systems.

“Our study underscores the significance of exploring seemingly trivial aspects of animal biology, such as excretion,” concludes Charita. “Investigating these processes reveals fascinating adaptations and illuminates how animals interact with their environments.”

“It also serves as a reminder that even in the most unexpected places, there’s still much to learn about the natural world.”

About our Experts

Elio Charita is a postdoctoral researcher at the Harvard Microrobotics Research Institute. He previously worked at Georgia Tech, where he studied how ultrafast invertebrates (including insects, hexapods, and arachnids) tackle challenges in fluid dynamics (e.g., feeding, excretion, predator evasion, etc.).

Jonathan Larson is an extension entomologist and assistant professor at the University of Kentucky, providing insect expertise for urban landscapes, turfgrass, nurseries, greenhouses, and household issues. He also co-hosts an informative insect podcast, Arthro-Pod.

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