False Widow Spiders Known for Biting People While They Sleep are on the Rise

False Widow spiders have been the subject of discussion among experts for years: judging by their name, one might assume that they're the benign counterparts to the universally-feared Black Widow. However, a new study from the National University of Ireland Galway has confirmed not only that the population of these arachnids is on the rise, but also that the bite of a False Widow can be so severe that it requires hospitalization.

Science Daily reported on the study, which was originally published in Clinical Toxicology earlier this week, noting that the Noble False Widow, or Steatoda nobilis, originally came from Madeira and the Canary Islands. It was first reported in Britain over 140 years ago, in the 19th century—however, its recent population boom means that the species is poised "to become one of the world's most invasive species of spider."

In certain regions of the world, the False Widow already reigns supreme: according to the study, in some parts of Britain and Ireland, the species has "become one of the most common species of spiders found in and around urban habitats."

Noble False Widow
The Noble False Widow spider is on the rise in the UK, and a new study suggests that its bite can be just as severe as that of a Black Widow. NUIGalway Press/Twitter

While experts aren't entirely sure what's causing the population increase, they suspect that "a new genetic mutation within the species may have made Noble False Widows more adaptable to new environments." They also attribute the shift to "an ever-increasing globalized economy," noting that the spiders have spread around the globe via "containers and crates." Now, the species is found in Europe, North Africa, West Asia, and parts of North and South America.

Perhaps most alarming is the fact that these spiders have gravitated towards "urban habitats," says Science Daily. And, as their numbers rise in densely populated areas, so are the number of people reporting bites—the symptoms of which can range from unpleasant to truly terrifying.

According to Science Daily, the symptoms of a False Widow bite can include "mild to debilitating pain and mild to intense swelling" in addition to "tremors, reduced or elevated blood pressure, nausea and impaired mobility." They also added that "in rare instances, victims have developed minor wounds at the bite site or had to be treated for severe bacterial infections."

Once these spiders have found their way into a new area, it appears that they're hard to avoid: the study found that "almost all bites occurred in and around the home" and that a whopping "88% of bites occurred when the victim was either asleep in bed or when the spider was trapped in clothing."

A team of scientists from NUI Galway have published a new study showing that Noble False Widow spiders can deliver a bite that requires hospitalisation. Epidemiology of bites reveals that almost all have occurred in and around the home. Learn more: https://t.co/rrHzBGGPEV pic.twitter.com/bLRKfXlLrA

— NUI Galway (@nuigalway) May 27, 2021

"In addition to their medically significant venom, Noble False Widows are extremely adaptable and competitive in the wild," said senior author of the study, Dr. Michel Dugon, who also runs the Venom Systems Lab at NUI Galway. "Two decades ago, this species was almost unknown in Ireland, the UK or in continental Europe. We still have much to learn about its genetics, origin, behavior and development. One thing is certain though: this species is here to stay, and we must learn how to live with it."