Cicada hum returns to Alabama as insects emerge from 13 years underground

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FRANKLIN, Ala. — Deep in a hollow in the Red Hills, the forest pulses with the swelling thrum of a million voices.
At first, the source of the loud humming sound is invisible. But stand still for a moment and stare at the tree limbs overhead. Before long you’ll see them: amber wings glistening like gold in the morning sun and thousands of pairs of eyes — all blood red — staring back at you.
After 13 years underground, millions upon millions of cicadas have emerged in Alabama during the last several weeks, most crawling out of their subterranean burrows within hours of each other — one of the natural world’s most impressive tricks.
John Cooley, a researcher at the University of Connecticut, has been in Alabama for several days, mapping the locations where the 13-year brood has hatched out.
“They can’t bite you, they can’t sting you, they can’t hurt you. They are harmless insects,” Cooley said. “But, they freak people out, partly because of the density, with so many emerging at once. They are a natural part of our environment. Enjoy them while they’re here because you won’t see them for 13 years.”
Insects emerging from eggs laid in 1998
The strange life cycle of a family of bugs known as “periodical cicadas” is one of the insect world’s great marvels. The members of the group now emerging all over central Alabama hatched from eggs laid inside the twigs of hardwood trees in 1998.
Falling to the ground, the tiny larvae dug into the soil until they found a nice tree root to sink their teeth into. Sucking sap for more than a decade, the cicada babies went through several transformations while underground. The bugs emerged en masse once soil temperatures reached a certain threshold, typically in the high sixties, according to scientists.
The forest floor in the Red Hills is littered with the crunchy brown husks the bugs shed as they emerged from the soil. Aside from the throbbing hum in the woods, the empty shells provide the best indicator of whether cicadas are present in an area.
Cooley said he had identified three different species in Alabama — Magicicada tredecim, Magicicada tredecassini, and Magicicada tredecula — all sporting black bodies, red eyes and amber wings. Those species are distinct from the so-called “dog day cicadas” that show up every summer in July and August, Cooley said.
The 13-year crop emerged several weeks ago, and the insects have moved high up in the forest canopy by now, Cooley said. They are still visible closer to the ground along the edges of the woods and in sunny clearings.
Across the state — points north of the city of Monroeville — they have seen the cicadas emerge, Cooley said, with that city serving as a rough estimate of the southern edge of the insect’s range.
Tunnel Springs, just north of Monroeville, is the southernmost point Cooley has seen the cicadas. He relies on reports made to his website magicicada.org to track the emergence of the insects.
Cooley encouraged people to report any sightings in their area to the site.
“We’ve never mapped in this part of the country in any great detail. If you look at the historical maps on our website, this place isn’t even covered. The maps don’t get into some of these back areas,” Cooley said, describing central Alabama