- House spider leg span
- Up to around 7 cm or more
- False widow body
- Females 8.5–14 mm
- Peak season
- September and October
- Risk
- Very low
Almost all UK spiders are harmless to people. The one that gets the headlines is the noble false widow, which has spread across southern Britain and can bite. Bites are very rare, and they're far less likely than a bee or wasp sting.
Signs of spiders and false widows
- Large, fast, brown spiders running across floors in autumn evenings (house spiders)
- Flat, sheet-like webs in corners, behind furniture and in garages
- Messy, tangled webs in window frames, sheds and outside lights (false widows)
- Thin, long-legged spiders hanging in ceiling corners (daddy-long-legs or cellar spiders)
How to be sure
House spiders are large, hairy and brown, with long legs and no shiny body. The noble false widow is smaller, with a shiny, bulbous, oval body in brown and cream, often with a pale crescent at the front, and legs without clear bands. It's easily confused with a harmless Steatoda relative or a garden spider, so a photo helps.
False widows are slow and shy. They tend to stay in their webs in window frames, sheds, conservatories and the corners of outbuildings, rather than running across rooms.
What you can do yourself
- Catch and release: put a glass over the spider, slide a piece of card underneath and take it outside.
- Vacuum up webs and egg sacs in corners, behind furniture and in garages.
- Seal gaps around windows, doors and where pipes enter the house.
- Fit fly screens to windows you leave open in the evenings in early autumn.
- Reduce clutter in sheds, garages and under beds, which gives spiders places to settle.
- Wear gloves when clearing sheds, window frames and outdoor furniture where false widows live.
Call a professional if
- You have large numbers of false widows around a child's bedroom window, a doorway or a play area and want them removed
- You run a business or rental where people are worried about bites
- Otherwise, rarely needed. Spiders eat flies, moths and other insects you'd rather not have
Safety: If you're bitten, wash the area with soap and water and use a cold compress. A pharmacist can advise on pain relief or antihistamines. Get medical help straight away if the bite swells a lot, blisters, turns into an open sore or looks infected. Call 999 if someone has difficulty breathing or swelling of the face or throat.
Keeping them out
- Keep outside lights off where you can, since they draw the insects spiders feed on
- Fill gaps around window and door frames
- Clear webs from window frames and sills regularly
- Store garden furniture and shoes off the floor in sheds and garages
Kit that helps
- Spider catcher or a glass and card
- Fly screens for windows
- Gloves for clearing sheds
- Vacuum with a crevice tool
- Sealant for window and door gaps
Product types only. We'll only ever point you to things we'd use ourselves.
Questions people ask
Are spiders coming inside to get warm?
Mostly not. Many house spiders were already indoors. In autumn the males wander looking for a mate, so you suddenly notice them.
Is the false widow dangerous?
It's not considered dangerous. Bites are very rare and usually happen when someone presses on or handles one. Most cause pain and swelling, and some become infected. Seek medical help if a bite swells badly, blisters or forms an open sore.
Do conkers or peppermint oil keep spiders away?
There's no good evidence that either works. Sealing gaps and reducing clutter does more.
Should I kill spiders?
There's no need. They're harmless to people and eat flies, moths and mosquitoes. Catch and release if you'd rather not share the room.
Are there poisonous spiders in the UK?
A handful of UK spiders can bite through human skin, including the noble false widow, but none is considered dangerous to healthy people.