In medieval Italy, a spider bite could send you into a dancing frenzy

There’s a chance that if you visited southern Italy during the Middle Ages, you might happen upon a port town where people were dancing uncontrollably in the streets. You’d find them frantically spinning, jumping…even crawling on the ground. But unlike the broader “dancing mania” that was taking place across Europe at the same time, this dance, dubbed the “tarantella,” was more than a sickness. It was also a cure. “Some people say that the bite of a spider caused people to tremor and shake,” Anna Harsh, a professional dancer and founder of the Allegro Dance Company, which specializes in Italian folk dances, tells Popular Science. They’d then continue moving to sweat out the poison. Tarantism is distinct from other dancing plagues Tarantism, a historical psychological and social phenomenon that led to anxiety, melancholia, and uncontrollable movement, ran rapidly throughout southern Italy from the 11th to the 17th century. The epicenter of tarantism was Taranto, a coastal city in southern Italy’s Puglia region, which occupies the “heel” of the country’s boot shape. Each summer harvest season, local residents would spend long days working in the fields where large, hairy wolf spiders burrowed. Most people believed that these wolf spiders carried a toxic venom. If they bit you, tarantism would quickly set in. The only cure would be to sweat out the venom through continuous, fast-paced dancing. We’re talking uncontrollable, flailing movements that would eventually exhaust both the dancer and the illness. Large, hairy, wolf spiders (Lycosa tarantula) are common across southern Italy. Image: Getty Images / Lastovetskiy Although southern Italy was the epicenter of tarantism, similar outbreaks of involuntary, convulsive dancing occurred throughout the Middle Ages. The first major recorded frenzy began on June 24, 1374 in Aachen, Germany. Soon after, others followed in countries like Switzerland and modern-day France. In many of these cases, those afflicted danced uncontrollably for days or weeks. Some even died dancing. Since these events happened centuries ago, no one really knows what caused them. But the tarantism of southern Italy and its ensuing tarantella dance both seem unique. The feared wolf spider that sparked the tarantella The name “tarantula” may have originated with the wolf spiders (Lycosa tarantula) of Taranto, but wolf spiders and tarantulas belong to two entirely different spider families. Still, with a leg span that can reach up to three to four inches across, multiple sets of eyes, and a series of odd, jerky movements when they walk, wolf spiders make easy targets for conspiracy theories and urban legends. While they can look frightening, science has determined over the years that a wolf spider’s bite is generally harmless to humans. Symptoms appear more like a mild bee sting, with a bit of localized pain and swelling, then a full-blown disco dance party. In fact, among the world’s 38,000 known spider species, only about 100 species have venom that is detrimental to humans. Related 'That Time When' Stories Do wolf spider bites actually make you dance? In August 1693, an anonymous Neapolitan doctor even tested the connection between the bite of a wolf spider and tarantism. He let two wolf spiders bite him in a public experiment, but the doctor never broke out into fancy footwork. Instead, modern science shows that the extreme summer heat, physical stress, dehydration, and even ample wine drinking could have easily caused the symptoms of tarantism. Still, the wolf spider and tarantism remain undisputedly linked. What is tarantella? Sometimes called the “Dance of the Spider,” the tarantella began as a ritual healing dance that aimed to sweat out any venom associated with tarantism. Many versions of the tarantella exist today, though they’re more traditional folk dances than medical treatments. Instead, the ‘tarantella as cure’ dance is more formally known as the pizzica. The word pizzica comes from the Italian verb pizzicare, which means “to pinch” or “to bite.” “Today we might think of that ‘bite’ as something internal, like stress or anxiety,” says Harsh. Picture when someone you know suddenly loses a loved one and they’re shaking uncontrollably. “That person will dance or move and do whatever they can to help them get through that situation.” Tarentella The Allegro Dance Company performs the tarantella at St. Francis University in Pennsylvania. Video: Tarentella, allegrodance Pizzica tarantata is performed almost like an exorcism, the spiritual practice of evicting demons or malevolent entities (such as supposed spider’s venom) through a sort of ritual—in this case, ecstatic, free-form dance. Musicians gathered around the inflicted victim, playing incessant, fast-paced 6/8-tempo rhythms driven by a tambourine, violins, and guitars. The person suffering from tarantism would then “go into a trance,” says Harsh. “There was shaking, hopping, swirling, and turning. Some people would roll on the ground and come back up. The pizzica has movements, but you can put them in any order. It’s however the spirit moves you.” Tarantism and the tarantella today These days, most historians and scientists agree that wolf spiders didn’t cause tarantism. Rather, tarantism was a form of mass hysteria, a situation where a group of people share the same intense fear, anxiety, or physical sickness—like dizziness, shaking, or stomach aches—even though there is no real physical or medical grounds for it. Tarantism mostly afflicted impoverished individuals, particularly women (tarantatas). One possible reason: “Women were oppressed and faced plenty of inequality,” says Harsh. “Dance is a way that they could express themselves, even scream, through movement. That they could be the center of attention for just a minute and be seen.” Over the centuries, the tarantella has become a celebration of life and joy rather than a frantic ritual. Italians often perform this now-beloved folk dance at weddings and festivals. Every August, La Notte della Taranta, Europe’s largest open-air festival dedicated to traditional folk music, the pizzica, and the tarantella, takes place in Italy’s Puglia region. Dancing as a cure Whether or not dancing works to sweat out a toxic venom, studies do show that dancing helps reduce stress and increases levels of serotonin, a hormone that helps regulate mood, sleep, and digestion. “You know, whatever is biting at us, whether it’s grief or loss, we can move together, follow the rhythm of a drummer, and heal ourselves in a sense,” says Harsh. “The movement just takes over and we stop thinking about our troubles.” Though if you do endure a lethal spider bite, we’d recommend the ER over two-stepping. In That Time When, Popular Science tells the weirdest, most surprising, and little-known stories that shaped science, engineering, and innovation. 2026 Popular Science Home of the Future Awards 39 products that will improve your everyday life.