Why are there spiders in my house – and what can I do about them?

Autumn is the time of year when you're most likely to spot a spider scuttling across your skirting board or lurking in the corner of a room.

And while we might prefer them to stay outside, most household spiders are harmless to humans – and would rather keep their distance from us, too.

With help from experts Bill Blumsom from the British Arachnological Society (BAS) and Niall Gallagher of the British Pest Control Association (BPCA), we explain how to identify and safely remove spiders from your home, what to do if you happen to be bitten by one (which, in the UK, is rare) and whether there's any truth to that age-old claim that conkers deter spiders.

In this guide:

• The most common spiders found in the UK 
• Conkers and other popular spider deterrents: fact or fiction?
• Spider prevention tips
• How do you safely remove a spider from your home?
• What to do if you're bitten by a spider

Look out for these five common household pests to watch out for as the temperature drops

The most common spiders found in the UK

The types of spider you're likely to encounter will depend on where you live. Here are some of the most common species found in UK homes, including those you might spot scuttling around in autumn as they search for a mate.

1. Large house spider (Eratigena species) – Large, brown, long-legged spiders with patterned abdomens. These fast-moving house-dwellers build funnel-shaped webs in quiet corners of homes, garages and sheds.
2. Common house spider (Tegenaria domestica) – A slightly smaller cousin of the large house spider, this species has a small, brown body with long, slender legs and a patterned abdomen. Like the large house spider, they are widespread and harmless, and build funnel-shaped webs in sheltered spots.
3. Cellar spider (aka. Daddy-longlegs spider) (Pholcus phalangioides) – Easily recognised by its tiny, pale-grey body and exceptionally long, thin legs, this spider hangs in untidy webs around ceilings and window corners in warm homes, garages and sheds and is increasingly widespread in the UK, particularly indoors.
4. Missing-sector orb weaver (Zygiella x-notata) – A medium-sized spider with a rounded abdomen bearing silvery-grey markings and relatively pale legs, it builds a distinctive circular web with a missing wedge near windows, fences and other outdoor structures.
5. Noble false widow (Steatoda nobilis) – A shiny, dark-brown spider with a bulbous abdomen that often has pale, skull-like or cream markings, it favours sheltered spots such as around window frames and is well established and increasingly widespread in southern England and Wales. Find out more about noble false widows and what to do if you find one in your home.
6. Laceweb spider (Amaurobius species) – This robust, hairy, dark-brown spider has an oval abdomen and subtle pale markings. It typically hides in dense, woolly-looking webs around cracks in walls, window frames, brickwork and garden crevices. 
7. Garden spider (Araneus diadematus) – Also known as the cross spider, this large, rounded spider is usually brown or orange with a distinctive white cross-shaped pattern on its abdomen. It's especially noticeable in late summer and autumn.

How long do spiders live?

A spider's lifespan depends on its species and sex, with females typically living longer than males.

'Most spiders live about a year, we believe, while the large house spiders and false widows can live about two years,' says Bill.

Conkers and other popular spider deterrents: fact or fiction? 

From conkers on windowsills to peppermint and citrus sprays, there are plenty of supposed tricks for keeping spiders out of your home. But do any of them really work?

We asked our experts to separate fact from fiction and explain why some popular deterrents might be best avoided, particularly if you have pets.

Do conkers deter spiders?

• Verdict: No convincing scientific evidence

You might have heard that placing conkers on your windowsills will keep spiders away, but there's no convincing evidence that this works.

'I wouldn’t rely on conkers to deter spiders,' says Niall. 'Current research doesn’t establish that putting conkers on windowsills keeps homes spider-free and a row of conkers isn’t a substitute for sealing gaps in your home.'

Conkers can also be dangerous for pets, particularly dogs that might be tempted to chew or swallow them.

'Conkers, like acorns, are highly poisonous to dogs if chewed or eaten, and can also cause blockages in your pet’s stomach,' says Caroline Reay, veterinary standards lead at pet charity Blue Cross.

'Although serious cases are rare, you should contact your vet straight away if you think your dog has eaten a conker.'

Does peppermint deter spiders?

• Verdict: Maybe, but more research is needed

There's some evidence peppermint oil can repel spiders, but that doesn't necessarily mean placing peppermint plants around your home or spraying peppermint oil will keep them away.

'Mint oil was shown to repel some spider species in a 2018 study, but responses varied,' explains Niall. 'That doesn’t establish that peppermint plants or homemade sprays will definitely keep spiders out of your home.'

Be particularly careful if you have pets, as peppermint oil can be toxic to cats and dogs.

'Peppermint oil can be toxic, especially to cats,' warns Caroline. 'It can cause mouth ulcers, stomach upset and – if there's enough of it at a high concentration – seizures.'

Does citrus deter spiders?

• Verdict: Probably not

The same study that investigated peppermint oil also looked into lemon oil as a popular spider deterrent, but found it had no effect on the three spider species they tested.

'Citrus is not a convincing option – I wouldn’t recommend lemon as a reliable deterrent,' says Niall.

Caroline also warns citrus oil can cause gastrointestinal upset in pets if ingested.

Do ultrasonic plug-in devices deter spiders?

• Verdict: No convincing evidence

Unlike humans, spiders don't have ears. Instead, they detect vibrations in a variety of ways, including via hairs on their legs.

Ultrasonic plug-in devices emit high-frequency sounds intended to repel pests. However, there's currently no convincing scientific evidence these devices are effective at keeping spiders out of your home.

'I'd save my money,' says Niall.

Do spider repellent sprays work?

• Verdict: Not reliably

Spider repellent sprays contain a variety of ingredients, including essential oils such as peppermint and citrus. However, as we've explained above, there's limited evidence these natural ingredients will reliably keep spiders out of your home.

It's also important to distinguish between sprays that kill spiders on contact and those that claim to repel them. As Niall points out, killing a spider doesn't demonstrate a product will keep others away.

'Killing a spider on contact doesn’t demonstrate lasting repellency,' he says.

If you do decide to use a spray, be particularly careful if you have pets, as some ingredients can be harmful.

'Spider repellents vary in ingredients, but many have essential oils like peppermint or citrus oil which can be harmful to pets, and others contain permethrin, which can be potentially toxic to cats,' warns Caroline.

Keep pets safe this winter with our advice on walking your dog safely in bad weather

Spider prevention tips 

While there's no foolproof way to keep spiders out of your home, there are some simple steps you can take to make it less inviting to them and the insects they feed on:

1. Declutter and vacuum regularly – Spiders favour quiet, undisturbed corners where they can hide and build webs, so keep your home clutter-free and vacuum regularly around skirting boards, behind furniture and under beds. See our vacuum cleaner reviews and our expert tips on decluttering your home.
2. Reduce insects in your home – Spiders are more likely to stick around where food is plentiful, so keep kitchen surfaces clean, store food in sealed containers and empty kitchen bins and food waste caddies regularly to deter insects. Read our food storage advice plus our expert maintenance tips to keep your kitchen sparkling.
3. Fill gaps and cracks around pipework, walls, windows and doors – Reduce the number of entry points available to spiders, including around pipes, skirting boards, window frames and external doors in particular. Take care not to block purpose-built ventilation openings, particularly those needed for gas appliances.
4. Use draught excluders on doors and windows – Draught excluders and door seals can help block gaps beneath external doors – see how to draughtproof your home.
5. Trim outdoor vegetation that touches your exterior walls or windows – Overhanging branches, climbing plants and shrubs touching your home can provide spiders with an easy route toward windows and doors. Trim vegetation back from the house and clear away leaf litter and garden debris near the walls to make access less convenient. If you're looking for reliable tools to get the job done, see our expert picks of the best hedge trimmers and best leaf blowers, and don't miss our list of essential garden jobs to get ready for winter.

Sealing gaps, reducing clutter and keeping on top of cleaning can help discourage spiders, but there's no guaranteed way to keep them out of your home.

If you do spot an eight-legged visitor, read on for our advice on how to remove it safely and humanely.

How do you safely remove a spider from your home?

Not everyone feels comfortable getting close to a spider, particularly a large one. But rather than reaching for the vacuum cleaner or squashing it, our experts recommend removing it humanely.

A glass or container and a piece of stiff card are all you need.

'Place the container over the spider, then slowly slide a stiff piece of card underneath, taking care not to trap its legs,' explains Niall. 'Keep the card against the opening while you carry it. Avoid picking it up with your bare hands.'

You should also think carefully about where you release the spider, particularly in colder weather.

'When rehoming a house spider, a sheltered garage or shed is better than an exposed lawn, especially in cold weather,' advises Niall. 'Some species are adapted to living in buildings.'

You can also buy humane spider catchers if you'd rather keep your distance.

What if you find a spider in the bath?

Contrary to popular belief, spiders found in baths haven't usually climbed up through the plughole. They've generally fallen in and become trapped because they can't climb the slippery sides.

'A towel draped over the edge can provide an escape route, if you’re happy for it to see itself out,' says Niall.

Are spiders getting bigger in the UK? 

There's no evidence UK spiders are generally increasing in size.

Some spiders reach their full size around this time of year, while mature males become more noticeable as they wander around looking for mates.

Are there any venomous spiders in the UK?

Almost all spiders have venom, which they use to subdue their prey.

'That sounds alarming, but it’s much more worrying for a fly than for you,' explains Niall.

Most UK spiders pose very little risk to humans, and only a small number of species can bite through our skin.

What are false widow spiders, and should you be wary of them?

False widows get their name from their resemblance to black widow spiders, but they generally pose little risk to humans.

The noble false widow is the species that's attracted the most attention in the UK, partly because of alarming media coverage about its bite.

'Bites can be painful and occasionally require medical attention, but the likelihood of being bitten is low,' explains Niall. 'Avoid handling them or trapping them against your skin.'

If you find a false widow in your home, there's usually no need to do anything. You can leave it undisturbed or follow our advice above on safely removing spiders.

What should you do if you're bitten by a spider? 

Spider bites are rare in the UK, but if you think you've been bitten:

• Wash the affected area with soap and water.
• Apply a cold compress or an ice pack wrapped in a cloth for at least 20 minutes if there's swelling.
• Avoid scratching the bite.

Speak to a pharmacist for advice on pain, itching or signs of infection. Contact your GP or NHS 111 if symptoms worsen, don't improve or you feel unwell. Call 999 if you experience difficulty breathing or sudden swelling of your lips, mouth, tongue or throat.

Which? expert view

Martha Roberts, Which? senior researcher

'A spider bite in the UK is likely to cause discomfort in varying degrees, depending on the species. It may look like other bug bites such as mosquito bites, possibly with one or two fang marks.

'They can cause redness, pain and swelling, or you might not notice them at all.

'As with many insect bites, you can reduce swelling with a cold compress and antihistamines, and manage pain and discomfort with painkillers, but speak to your pharmacist or GP if you're concerned – for example, if the bite appears to have become infected.'

See how to identify and treat spider bites with our handy guide