A lady in Hoboken, New Jersey was out for a morning walk in a park near the Hudson River on March 25, when she spotted hundreds of worms spread along the walkway.
The woman, who asked that she not be identified, told Live Science that on looking closer, she noticed something even more strange about the worms – many of them had formed a cyclone-like shape with their bodies. The spiral of living worms was where the grass met the edge of the concrete.
Well, the lady took a picture of the “wormnado,” and sent it to Tiffany Fisher, a Hoboken City Council member who in turn, shared the photos to Facebook with a caption: “Clearly worms come out after it rains, but this is something I’ve never seen!”
What caused the spiral shape?
The cyclone-like shape baffled many scientists. There were no pipes closeby, and not all the worms were in the spiral. There were still plenty of worms spread out on the sidewalk or clinging to the wall of a nearby building, and dribbling down into the road from the curb.
“This tornado shape is really interesting,” Kyungsoo Yoo, a professor in the Department of Soil, Water, and Climate at the University of Minnesota, told Live Science, according to the Huffington Post. But he didn’t have a clue about the shape and said he had never before seen earthworms in a spiral.
Saad Bhamla, assistant professor of Georgia Tech’s School of Chemical and Biomolecular Engineering, speculated that sudden changes in water in the soil and the shape of the landscape could have contributed to the worm arrangement.
“The ground there could be dipped,” Bhamla told Live Science in an email. “If the water drained that way after flooding, the worms could be following a water gradient.” It’s difficult to tell the worm species from the photos, but Bhamla and his colleagues have observed that type of behavior in the aquatic blackworms they study, which form massive blobs.
Bhamla, the head of the Bhamla Lab at Georgia Tech, says the lab has studied aquatic California blackworms, (Lumbriculus variegatus), and they can form an enormous living knot — known as a blob — of as many as 50,000 worms when they’re threatened by dry conditions.
“We’ve seen them follow trails of water and form all kinds of paths and aggregate structures,” Bhamla said. “These aggregations occur once water leaves.” However, as it’s unknown what type of worms made the spiral, any conclusions about their behavior would be speculation, Bhamla added.
Local weather reports showed that the area had received about 1 inch (2.5 centimeters) of rain before the earthworms had come out. Earthworms have no special respiratory organs. Oxygen is exchanged through the moist skin and capillaries, so with heavy rainfall, the earthworms come to the surface to keep from drowning.
Harry Tuazon, a doctoral candidate in Georgia Tech’s Interdisciplinary Bioengineering Graduate Program, told Live Science in an email: “I think the circular pattern is much more indicative of water draining and the worms being swept, rather than a type of behavioral locomotion,” Tuazon said. “Perhaps a sinkhole is forming? It would be interesting if a bunch of earthworms provided telltale signs of a forming sinkhole!”
