False Widow Spiders in the UK: Facts, Risks and What to Do

False widow spiders (Steatoda species) have attracted significant media attention in recent years, and concerns about them are common among London homeowners. This guide cuts through the sensationalism to give you an accurate picture of the risk they pose and when to seek professional help.

What Are False Widow Spiders?

The term "false widow" refers to several species in the Steatoda genus that resemble the true black widow spider (Latrodectus species). The most commonly encountered species in London is the Noble false widow (Steatoda nobilis), a large, dark spider with a distinctive bulbous abdomen marked with cream-coloured patterns.

Are False Widow Spiders Dangerous?

False widow spiders can bite if handled roughly or accidentally trapped against skin. Their venom can cause localised pain, swelling and redness — similar in severity to a wasp sting. Severe reactions are extremely rare. There are no verified deaths attributable to false widow bites in the UK.

The majority of spider bites attributed to false widows are, on investigation, found to be skin infections or bites from other arthropods. Healthy adults are at minimal risk from false widow spiders, though anyone with compromised immunity should exercise more caution.

Where Are They Found?

False widows favour undisturbed locations in and around buildings: - Window frames and the outside of buildings - Garages and outbuildings - Loft spaces and eaves - Under kitchen and bathroom fixtures - Garden sheds

When to Consider Professional Treatment

- When false widow spiders are present in large numbers throughout a property - When someone in the household has been bitten and the GP has confirmed a spider bite - When egg sacs are present (each can contain dozens of eggs) - When spiders are present in a school, nursery or care setting

What Professional Treatment Involves

A professional treatment plan may combine removal, targeted treatment and exclusion measures after the species and harbourage areas are assessed.

Enquiries temporarily unavailable for a professional assessment.