False widow spiders: Guidance from Public Health England

PHE (Public Health England) has been made aware that there have been a number of infestations of false widow spiders in London.

It is normal to see more spiders at this time of year as they come indoors for warmth. False widow spiders are native to the UK, and are common in Southern England. They are most active at night; during the day they tend to remain within or near their webs.

Spider bites are rare in the UK. The false widow spider can bite, but does this only if provoked or disturbed.

Although they are mildly venomous, venom is rarely used in a bite. The bites leave small puncture marks on the skin, and cause localised pain and swelling. Pain from a false widow spider bite is similar to that of a bee or wasp sting, and usually resolves one to 12 hours after the bite.

More significant problems are associated with secondary infections than with the bite itself. If you come across a false widow spiders avoid handling or disturbing their web. If you are bitten, clean the bite with soap and water to prevent it from becoming infected.

It may seem unpleasant to have more spiders than usual inside, but they do not pose a significant public health risk. As with all spider species, eradication treatment cannot ensure that the spiders will not return to the building.

For further advice on insect bites and stings visit Natural History Museum, Fact sheet: false widow spider.