The United Kingdom is experiencing a rise in venomous false widow spider bites, prompting experts to warn of potential public health issues. Figures from the NHS show a significant increase in hospital admissions linked to spider bites, rising from 47 in 2015 to 100 in 2025. This increase is attributed, in part, to the proliferation of a non-native species, Steatoda nobilis, commonly known as the noble false widow.
The Noble False Widow
The noble false widow, which arrived in the UK aboard cargo ships in the 19th century, has spread rapidly in recent years, a phenomenon experts link to warmer temperatures influenced by climate change. These spiders, roughly the size of a £2 coin, possess venomous fangs capable of delivering a painful bite. Biologists suggest that these bites can potentially lead to anaphylactic shock and severe infections, including sepsis, a life-threatening response to infection.
Clive Hambler, a lecturer in biological and human science at Oxford University's Hertford College, describes the noble false widow as the most dangerous spider breeding in Britain and an emerging threat to public health. He notes that their numbers have grown significantly since the 1980s, when they were much rarer, and they are now increasingly common across the country.
Nature of Bites and Reactions
False widows typically build tangled webs in sheltered areas such as traffic lights, railings, window sills, and greenhouses. They are also known to shelter in dark, warm places, including shoes and beds. Conservation charity Buglife states that false widows do not actively attack humans, but bites can occur if a spider is inadvertently pressed against skin, such as when putting on clothing or sitting down.
However, Hambler has described the species as being more prone to bite than generally understood, noting instances where spiders have approached larger organisms and bitten when disturbed. Many bites are reported to occur when people roll onto spiders in their beds or when professionals like plumbers or electricians disturb their webs in dark spaces.
The venom of the false widow contains cytotoxins that can liquefy prey and, in humans, can cause a condition known as steatodism. Symptoms include intense pain radiating from the bite site, swelling, redness, fever, and nausea. While the risk of anaphylactic shock is debated among scientists, some experts warn that bites can also trigger sepsis. There are also concerns that the fangs of these spiders may harbor antibiotic-resistant superbugs, complicating treatment for infected bites.
Documented Cases
Recent cases highlight the potential severity of false widow bites. Adam Abrehart, from Bedfordshire, experienced severe symptoms after a suspected false widow bite on his leg, which developed into cellulitis, a bacterial skin infection. Doctors treated him with strong antibiotics after the tissue around the bite died.
In a more tragic instance, a student named Harry Bolton died from sepsis following a suspected spider bite on his back, which led to a significant open wound. An inquest concluded that the bite likely contributed to his death.
Other UK Spiders and Prevention
While the noble false widow is considered the most concerning, other common UK spiders such as the giant house spider, the woodlouse spider, and the garden cross spider can also bite if provoked. However, their bites are not known to cause significant medical consequences.
Experts emphasize that spider bites in the UK, even from the false widow, remain relatively rare. Dr. Danniella Sherwood of Buglife suggests that increased reporting might be due to greater public awareness and anxiety, with many unconfirmed cases being mistaken for other ailments. She advises simple precautions, such as routinely shaking out clothing, footwear, and bedding before use, and suggests safely relocating spiders found indoors rather than attempting to eliminate them entirely.
If bitten, the advice is to wash the bite with soap and warm water. If redness, swelling, or pain develops within 24 to 48 hours, medical advice should be sought, particularly if symptoms worsen or signs of infection appear. In cases of severe allergic reaction or symptoms indicative of sepsis, immediate emergency medical attention is crucial.