Virginia mom Abby Doble’s five- and seven-year-old are ready for some noisy visitors. “They still have old exoskeletons they collected last year,” she says. But those exoskeletons were from annual cicadas. What’s coming now is bigger … much bigger.
Think: trillions of insects. This is “Brood X” (as in “Brood 10”), a regional group of periodical cicadas that emerges just once every 17 years. If you live in one of the states that’s expecting the bevy of bugs, your kids are likely feeling the excitement. Here’s the buzz on what’s up with these visitors—and ways their arrival can help teach children some six-legged STEM.
Why the cicadas are here
© Photograph by DARLYNE A. MURAWSKI / National Geographic Image Collection A Brood X nymph emerges from a hole in the ground, called a chimney.
The periodical cicadas you’ll see this spring and summer are actually the grown-up insects that hatched 17 years ago, when their parents emerged. After spending most of their lives tunneling underground, these cicadas will be aboveground for about a month.
“Their sole purpose when they’re in that stage is to mate, lay eggs, then die,” says Megan Abraham, division director and state entomologist in Indianapolis.
But while they’re here, they’re loud—at least the males are. “They have something called a tymbal in their abdominal cavity, and it acts like a drum,” Abraham says. “They have tiny muscles that pull on this drum, and that calls the females.”
That makes one big bug party that in some places can sound like a running freight train is nearby. In Indiana, one of the Brood X “epicenters,” as many as 1.5 million buggers per acre are expected to emerge.
Experts theorize that the massive group appearance is so that predators like birds and rodents can’t possibly eat them all, which would prevent mating. Once the survivors do mate, the cicadas lay eggs in trees, where the nymphs (baby cicadas) will hatch and drop to the ground, burrow in, and live underground. There, they’ll start sipping from grass roots, then graduate to tree roots for the next 17 years.© Photograph by cmannphoto / Getty Images A newly molted Brood X cicada emerges from its exoskeleton.
Harmless to humans
With a three-inch wingspan, these red-eyed buggers might look alarming. But they’re more like the golden retrievers of the insect world—mostly harmless and a little clumsy. “They don’t bite or sting,” Abraham says. “But they’re not very good about flying, so they’ll be hitting cars and running into people.”
The swarms aren’t like locusts, which eat and destroy crops. In fact, they’re good for local wildlife, which feed on the bugs. After the cicadas come and go, “there will be quite a boom of fat squirrels and raccoons,” Abraham says. And barring unusual allergies, even your dog or cat can munch a few. (Humans have been known to eat them, too—they’re said to taste like shrimp.)
Cicada STEM activities for kids
Best of all, kids can learn a lot from cicadas that will inspire them to explore science and nature. “Having first-hand experiences with the cicadas sets kids up to really understand more complex scientific concepts later,” says Rebecca Haverstick, an elementary school science teacher in New York. For instance, a young child who hears a cicada’s calls traveling long distances now might easily grasp a lesson on sound waves years later.
Here are some fun (and—sh!—educational) activities for this season of cicadas.
Guess their stage. When Brood X first emerges, the cicadas go through several different developmental stages that kids can observe. The emerging nymphs look light brown “to blend in with the soil,” Abraham says. Right away, they start climbing the nearest tree, then pop out of their exoskeletons. “As soon as they come out of their molt, they’ll be a white color,” Abraham says. Their wings will be light white and soft. Over the next few hours, their wings will open and firm up as their bodies turn golden and, finally, jet black. Then they are called adults—and it all happens in about a day.
Be a cicada detective. Cicadas leave telltale signs where they emerge and lay eggs. Checking below a tree, kids might find little tube-shaped mounds of earth that the cicadas created when they first came out from underground. Children can also look for “egg scars”—little slits on young branches where the cicadas have laid their eggs.
Do a sound experiment. Periodical cicadas are famously noisy—a single bug can be about as loud as a lawnmower! Kids can see just how loud the bugs are with a sound wave experiment. Tightly stretch plastic wrap atop a bowl and attach with a rubber band. (Save the wrap for later!) Put crumpled snips of tissue paper on top of the wrap. Then take it outside and set it on the ground beside a loud cluster of cicadas. The bits of paper should jump and move. “Sound is vibration traveling through air,” Haverstick explains, noting that the cicadas’ vibrations are strong enough to move the pieces of paper.
Feel cicada “honeydew.” Kids who stand under a tree full of cicadas will feel a few drops of liquid falling. Its official name is “honeydew,” but it’s better known as cicada pee! “It can kind of feel like a shower sometimes, depending on how many are in the tree,” Abraham says. Gross as it might seem to grown-ups, it can get kids talking about the fact that cicadas need to pee and poop, just like we do—and that’s the start of understanding digestion.
Attract a cicada. Females let males know they’re interested by clicking their wings in between male cicada songs—and the clicking sounds a lot like a kid snapping fingers. “Female wing flicks are sometimes placed between song phrases or within the last part of the song phrase,” explains Chris Simon, professor of ecology and evolutionary biology at University of Connecticut, and a specialist in cicadas. “If a kid can get close to the cicadas, then they can hear individual songs and try clicking to them,” she says. That gives kids the chance to closely see, hear, and even feel the weight of a cicada. (Just make sure to let it rest on your body, then fly away when it’s ready.)
Article by Jamie Kiffel-Alcheh for National Geographic©