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You don't have any saved articles. + add current article to list BRITISH WILDLIFE How dangerous are false widow spiders? By Emily Osterloff 144 Every autumn there are reports of false widow spiders becoming uninvited eight-legged houseguests in homes across the UK. But despite looking similar to the more dangerous black widows, all these spiders are likely to do is give you a small and relatively harmless bite. It might seem like false widow spiders make a dash for your home as soon as the weather gets chilly, but they can actually be seen inside year-round. Temperature may be one cause of the arachnid exodus as they attempt to get out of the cold, but some may have long gone unnoticed in the darkened corners of the house. What does a false widow look like? False widows - species in the genus Steatoda - are sometimes confused for black widow spiders - species in the genus Latrodectus - and are mistakenly thought to be as dangerous. Both groups of spiders have a similar dark-coloured, globular body. The name false widow is given to species in the genus Steatoda. Six false widow species live permanently in the UK. The three most common false widows are: the rabbit hutch spider, Steatoda bipunctata the cupboard spider, Steatoda grossa the noble false widow, Steatoda nobilis The Mediterranean false widow spider, Steatoda paykulliana, is also an occasional visitor to the UK when it is accidently imported with produce. Each species is fairly distinct in colour and size, with unique sets of markings on their abdomens. Find out how to identify a false widow spider and work out which species you have seen. This is a cupboard spider, Steatoda grossa. It is one of the three most common false widow species in the UK. Its body is usually between 4.5 to 10 millimetres long. © thatmacroguy/ Shutterstock Noble false widows The noble false widow is most commonly reported. It is the largest of the UK's three most common false widow species, reaching a body length of between seven and 14 millimetres, with the females typically larger than the males. The noble false widow was first recorded in the UK in the 1870s - likely a stowaway on cargo ships from its native Madeira and Canary Islands. But it is only since the 1980s that the species has gained a strong foothold, forming established populations in the majority of the southern counties - although it has now spread northwards. Noble false widows are usually seven to 14 millimetres long, with distinctive skull-shaped markings on their backs. © thatmacroguy/ Shutterstock Their webs are usually suspended at least 1.5 metres off the ground to allow the spiders to hunt flying insects. In homes they often prefer to skulk in kitchens and conservatories. Their webs are a tangle of threads, a characteristic of all false widow species. The pattern on their bodies is often described as 'skull-shaped', which probably doesn't help their negative reputation. Spiders often mistaken for false widows There are also plenty of other spiders that also cause confusion in homes and gardens across the UK. Two of the most common are the missing sector orb weaver (Zygiella x-notata) and the lace webbed spider (Amaurobius sp.). The missing sector orb-weaver can be mistaken for a false widow, although it is not known to bite humans © shaftinaction/ Shutterstock Both species, like false widows, are found all over the UK. The latter is also known to be a biter, although with similar (or even less) pain as a result, and few lasting symptoms. Lace web spiders are most often found outdoors, building their webs on fences, sheds, walls and any general clutter lying about. The missing sector orb weaver, however, is more of an indoors spider. Most homes in the UK are likely to have this spider in residence. This species is one of the few spiders that will feed through the winter, as long as there is plenty of food available. The lace web spider is mostly found outdoors. Their colouration and pattern leaves them often mistaken for a Steadota species © Ian Redding/ Shutterstock Are false widows dangerous? There are over 650 species of spider known to live in the UK. Only around 12 of these are recorded as species that have bitten humans. So, if you see a spider, the likelihood is that it is just a harmless, common British spider. False widows are not the deadly spiders they are sometimes thought to be. Although false widows do have a venomous bite, the venom is not particularly potent. Usually the only symptom is pain at the site which may radiate away from the bite. It ordinarily lasts between one and 12 hours, and rarely for more than 24 hours. Often, the symptoms are no worse than the pain of a wasp sting. Males are more prone to biting. But this is only because they leave the nest in search of a mate, often venturing indoors looking for females. They are only known to bite when provoked or trapped against skin. The rabbit hutch spider, Steatoda bipunctata, is found commonly across the UK, and can be found in most British gardens © thatmacroguy/ Shutterstock There are sometimes reports of false widow bites that present with more sinister symptoms like rotting flesh and excruciating pain. But these are usually not backed up with formal spider identification. The extreme side effects experienced are most likely the result of a secondary infection, likely bacterial, if the wound is not kept clean. There is often hysteria surrounding these spiders, and they have unjustly earned a reputation for being a dangerous pest. But these spiders only bite when they feel threatened. Should I kill a false widow spider? Jan Beccaloni, Curator of Arachnida and Myriapoda, says 'During my time at the Natural History Museum I have, not surprisingly, met many people who are scared of spiders. That’s a great pity because spiders are awesome creatures which are sadly misunderstood.' 'Aside from their key role in feeding on pest insect species, their silk is being developed to make specialist clothing such as bullet-proof vests and their venom can be used in pain relief.' 'So next time you find an unwanted spider in your house, please don’t kill it! Either leave it in peace, or humanely put it out in your shed.' False widows can live in relative harmony with us - they're even tidy houseguests, helping to keep our homes clear of flying insects and other pesky invertebrates. We hope you enjoyed this article… ... or that it helped you learn something new. Now we're wondering if you can help us. Every year, more people are reading our articles to learn about the challenges facing the natural world. Our future depends on nature, but we are not doing enough to protect our life support system. British wildlife is under threat. The animals and plants that make our island unique are facing a fight to survive. Hedgehog habitats are disappearing, porpoises are choking on plastic and ancient woodlands are being paved over. But if we don't look after nature, nature can't look after us. We must act on scientific evidence, we must act together, and we must act now. Despite the mounting pressures, hope is not lost. Museum scientists are working hard to understand and fight against the threats facing British wildlife. For many, the Museum is a place that inspires learning, gives purpose and provides hope. People tell us they 'still get shivers walking through the front door', and thank us for inspiring the next generation of scientists. To reverse the damage we've done and protect the future, we need the knowledge that comes from scientific discovery. Understanding and protecting life on our planet is the greatest scientific challenge of our age. And you can help. We are a charity and we rely on your support. No matter the size, every gift to the Museum is critical to our 300 scientists' work in understanding and protecting the natural world. From as little as £2, you can help us to find new ways to protect nature. Thank you. Donate now 144 British wildlife Spiders Urban wildlife Venom Related information View our guide to identifying spiders in your home Get to know common UK spiders through their dating profiles British wildlife Find out about the plants and animals that make the UK home. Get closer to nature Discover more British wildlife Spider webs: not just for Halloween Explore seven common styles of spider web and discover the arachnids that make them. British wildlife Finding love on the web Spiders may seem scary, but most of them are just looking for love. 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