Thousands of earthworms writhe on top of dirt and sidewalks during spring rains. However, heavy rains in a town near New York City were recently accompanied by something a little different: a wormnado.
On March 25, a resident of Hoboken, New Jersey was out for a morning walk in a park near the Hudson River when she saw hundreds of worms strewn around the route. After her initial surprise, the woman discovered something much more bizarre: a variety of the worms had developed a cyclone-like pattern, forming a vortex where the edge of the grass met the pavement, according to Live Science.
Tiffanie Fisher, a member of the Hoboken City Council, posted the photos of the “tornado of worms” on Facebook after the woman took them. “It’s obvious that worms emerge when it rains, but this is something I’ve never seen!” Fisher wrote about it in his blog post.
The worm tornadoes weren’t deliberately spiraling when the photographer saw them, while individual worms still wriggled in place, she told Live Science. There were no open pipes nearby, and despite the fact that most of the worms were stretched out in a wide swirl, there were plenty of worms stretching beyond the wormnado’s outer curve; they clung to the wall of a nearby building and dribbled down the curb and into the lane, according to the lady.
Although it’s possible to think the worms were aligning themselves in a spiral in anticipation for the Worm Moon — the supermoon that shone brightly in the night sky only a few days later on March 28 — the spiral is impossible to be a celestial ceremony. So, what exactly was this strange wormnado all about?
According to the University of Wisconsin–Madison, worms breathe through their skin, because when strong or constant rain saturates the soil with water, they must tunnel to the surface or avoid drowning. Earthworms are usually solitary, but when they’re on the floor, they may form herds. Researchers stated in the International Journal of Behavioural Biology in 2010 that the worms congregate in groups and consult with one another about where to go.
Earthworms of the species Eisenia fetida formed clusters and “influenced each other to choose a common direction during their migration,” according to the researchers, and they did so using contact rather than chemical signals. According to the report, this mutual behaviour may help earthworms withstand environmental threats such as floods or arid land, as well as serve as a defensive mechanism against predators or pathogens.
Rangers at Eisenhower State Park in Denison, Texas, caught an extraordinary case of earthworm herding on camera in 2015. Several massive masses of pink earthworms wriggle on a path in videos uploaded to the Texas Parks and Wildlife YouTube website.
In a video summary, park representatives wrote, “Recent flooding might have brought out this herding activity.”
The cause of the Hoboken wormnado, on the other hand, is less obvious. “This tornado form is very fascinating,” said Kyungsoo Yoo, a professor at the University of Minnesota’s Department of Soil, Water, and Climate. Yoo studies how invasive earthworms alter forest habitats, and despite the fact that worms are notorious for mass-emerging from soil after storm, he had never seen them form a spiral before, according to an email from Yoo to Live Science.
When threatened by dry conditions, aquatic worms such as the California blackworm (Lumbriculus variegatus) will build a massive living knot — known as a blob — with up to 50,000 worms, according to “Worm Blobs,” a comic developed by the Bhamla Lab at Georgia Institute of Technology’s School of Chemical and Biomolecular Engineering and illustrated by artist Lindsey Leigh. Bhamla Lab researchers wrote in the comic that a densely packed blob of worms is less likely to dry out than a single worm, and the worms tug and push to pass the blob around.
In an email, lab leader Saad Bhamla, an assistant professor at Georgia Tech, proposed that the presence of a spiraling wormnado could be explained by abrupt changes in the soil’s water, combined with the shape of the terrain.
In an email to Live Science, Bhamla said, “The land there might be dipped.” “The worms could be following a water gradient if the water drained that direction after floods.” The worm species can’t be determined from the photographs, but Bhamla and his colleagues have seen similar behaviour in the marine blackworms they research, which form large blobs.
Bhamla said, “We’ve seen them follow water trails and form all sorts of pathways and aggregate structures.” “As soon as the water evaporates, these aggregations form.” However, since the kind of worms that produced the spiral is unclear, all assumptions regarding their actions are speculative, according to Bhamla.
Rainfall totaled around 1 inch (2.5 centimeters) the night before the photographs were taken, according to local weather forecasts. According to Harry Tuazon, a doctoral candidate in Georgia Tech’s Interdisciplinary Bioengineering Graduate Program, “it would have culminated in a lot of earthworms falling out of the soil for air.”
“I believe the circular pattern is more reflective of water drainage and the worms being swept than of behavioral locomotion,” Tuazon said. “Is it possible that a sinkhole is forming? It’d be fascinating if a swarm of earthworms gave away the presence of a sinkhole in the making!”
Whatever triggered the wormnado in Hoboken, it didn’t last long. The swirl had vanished by the time the woman who photographed it returned to the park a couple hours later.
“There were already a lot of worms on the windows, the curb, the pavement, and the driveway. However, the majority of it had vanished — I’m not sure where they went “she said