In a groundbreaking discovery, scientists have observed tiny nematode worms forming “superorganisms” by creating towering structures in the wild, a behavior previously only observed under experimental conditions. This phenomenon, captured by researchers in Germany, challenges the earlier assumption that the behavior was driven by competition. According to a recent paper published in Current Biology, the observations of nematode worm towers forming in local orchards suggest a more cooperative behavior at play. This behavior, described as mass transit or group movement, offers new insights into how these tiny creatures navigate their environment. The research was conducted by the Max Planck Institute of Animal Behavior (MPI-AB) in collaboration with the University of Konstanz.
The Discovery of Nematode Towers in the Wild
Previously, nematodes forming towers had been observed only in laboratory settings, with scientists speculating that the behavior was competitive—a way for the worms to escape from one another. However, new images and video footage taken from local orchards in Konstanz, Germany, have now revealed these worm towers forming naturally on fallen fruits such as apples and pears. The presence of these towers in nature hinted at a more mutualistic motivation, rather than individual competition for survival. As researchers continued to observe, they confirmed that these structures were not only naturally occurring but a form of mass transit, helping the worms move more efficiently across their environment.
“I was ecstatic when I saw these natural towers for the first time,” said Serena Ding, senior author and group leader at MPI-AB, reflecting on the moment when Ryan Greenway, a biologist at the University of Konstanz, shared the first video recording from the field. “For so long natural worm towers existed only in our imaginations. But with the right equipment and lots of curiosity, we found them hiding in plain sight.” This discovery marks a significant milestone in our understanding of how these tiny organisms interact and cooperate in nature.
Towering Behavior: A New Form of Cooperation
The towering structures formed by these nematodes are not simply random clusters of worms. According to Daniela Perez, the first author of the study and a postdoctoral researcher at MPI-AB, “A nematode tower is not just a pile of worms. It’s a coordinated structure, a superorganism in motion.” This cooperative behavior is a novel way for these tiny creatures to move as a group, making it easier for them to travel across difficult terrain. The study also found that only worms in a specific larval stage—known as “dauer”—participated in the tower building, indicating that this behavior is not random but likely driven by genetic or environmental factors that influence development at this stage.
Interestingly, the research also provided insights into how these towers function. The worms seemed to “sense” their environment and adjust their formation accordingly. “The towers are actively sensing and growing,” Perez said. “When we touched them, they responded immediately, growing toward the stimulus and attaching to it.” This responsiveness suggests that the towers are not passive structures but dynamic systems that react to environmental cues, making them a highly efficient form of collective movement.
A Comparison to Other Superorganisms in Nature
The concept of a “superorganism,” where individual members of a species work together to form a single, functioning unit, is not new in the animal kingdom. Similar behaviors have been observed in slime molds, fire ants, and spider mites. However, the behavior exhibited by these nematodes represents a new example of such cooperative movement among worms. Researchers were curious whether this behavior could be replicated in other species of worms, so they conducted a series of experiments with roundworms (Caenorhabditis elegans), a model organism used in biology and behavioral studies.
In a laboratory setting, researchers used a toothbrush bristle as a scaffold on an agar plate and introduced the roundworms into the setup. Within two hours, the worms had formed a tower, demonstrating that this towering behavior is not exclusive to nematodes in orchards but could be a more generalized strategy for group movement in other types of worms. “Our study opens up a whole new system for exploring how and why animals move together,” said Ding. This experiment suggests that, far from being a rare occurrence, this kind of cooperative structure could potentially be observed in many other species that rely on social or group-based behaviors to navigate their environments.