It’s Not an Invasion — It’s Spider Mating Season, and Here’s What Actually Keeps Them Out

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I found a spider in the bath on the 9th of September this year. Not a small one — one of those long-legged giants that looks like it’s been lifting weights, sitting dead centre of the tub like it paid rent. I did the normal British thing: stood in the doorway, phone in hand, weighing up whether this was a “get a glass” problem or a “close the door and pretend the bathroom doesn’t exist until my partner gets home” problem.

Turns out I wasn’t the only one having that exact moment that week. Search interest in “spiders in house” spikes every year in the second and third week of September, and it’s not because spiders are invading — it’s because it’s their dating season, and the males have places to be.

That distinction matters more than it sounds like it should, because it changes what actually helps. A spray that’s brilliant against a colony living in your loft does very little against a single wandering male who’s already inside and just trying to find his way back out. This guide has been rewritten from the ground up to reflect that — the biology, the products that suit each situation, and the bits of UK-specific safety advice that a lot of spider content skips over entirely.

How We Chose These Products

Every product below is currently sold and stocked on this site, so nothing here is a dead link to something that’s out of stock or discontinued. Beyond availability, we looked for four things: a real UK retail presence (not an unbranded listing with no history), a mix of lethal and non-lethal options since not everyone wants to kill a giant house spider just for existing, honest pricing with no inflated “was £40, now £12” theatre, and enough verified customer feedback that we weren’t just taking a manufacturer’s word for it. We also deliberately avoided ultrasonic-only “repellers” as a sole recommendation — the evidence that they work on spiders specifically is thin, and we’d rather tell you that than sell you one.

Quick Comparison: The 5 Products Worth Knowing About

Why Your House Feels Like Spider HQ Right Now

The Natural History Museum has been fielding the same “spider invasion” headlines every autumn for years, and their researchers keep saying the same thing: it’s not an invasion, it’s dating season. From early September through to mid-October, male spiders of species like the giant house spider (Eratigena atrica) leave the webs they’ve spent all summer building and go looking for females. That’s why you suddenly see them sprinting across the kitchen floor at 11pm, or find one stuck in the bath — baths and sinks have smooth, curved sides a spider can walk down but can’t climb back out of, so it just… stays there, looking enormous and vaguely apologetic.

Research from the University of Gloucestershire’s citizen-science spider surveys found that sightings peak around mid-September, and that males make up more than 80% of the spiders people report seeing indoors during that window. The females, mostly, are still tucked away in the webs you never notice — behind the boiler, under the stairs, in the shed. The ones you’re seeing are the ones actively travelling, which is also why sealing gaps and using entry-point deterrents works better than trying to “clear the house” of spiders that were never really invading in numbers to begin with.

The UK has around 650 recorded spider species, though only a handful ever show up indoors in any numbers. The ones worth knowing by sight:

Giant house spider (Eratigena atrica) — the UK’s biggest, with a leg span that can reach 7–8cm. Harmless, but the one most likely to trigger a genuine scream. It’s a wandering hunter rather than a web-builder once mature, which is exactly why glue traps at floor level work so well against it.
Garden spider (Araneus diadematus) — the classic orb-web spider with the cross-shaped marking on its back. Mostly stays outdoors; if you see one indoors it’s usually just passing through.
False widow (Steatoda nobilis) — glossy, dark brown/black, roughly the size of a 50p coin. This is the one people worry about, and the one BPCA has published specific guidance on (more below).
Daddy long-legs spider (Pholcus phalangioides) — the pale, long-legged one that hangs upside down in a loose web in corners and cellars. Almost never bites, and actively preys on other spiders.

The web-builder versus wanderer distinction is worth holding onto, because it’s the whole reason a “one product fixes everything” approach tends to disappoint people. A garden spider that’s spun an orb web across your porch light isn’t going anywhere near a glue trap on your kitchen floor — you’d need to physically remove the web instead. A giant house spider that’s given up web-building for the season and is actively hunting for a mate, on the other hand, is exactly the animal a floor-level glue trap or a scent barrier at the door is designed to intercept. Matching the product to the behaviour, rather than just buying “the strongest spray,” is most of what separates a household that gets on top of its September spider problem from one still finding new ones in November.

The Five Products Worth Knowing About

1. Pest Guard Spider Catcher Stick — £9.99

This is the tool for anyone who’d rather not kill anything, and honestly the one we’d point most households toward first. It’s a long-handled catcher with soft bristles that gently trap a spider so you can carry it outside and let it go, without the ten-minute stand-off of trying to coax one into a glass.

Pros: No chemicals at all, works on species you’re not sure how to identify (better to catch and release than guess), genuinely reduces the “ugh” factor of dealing with a big one.
Cons: Does nothing for prevention — it only solves the spider that’s already in front of you.
Best for: Households with an arachnophobe who still doesn’t want spiders harmed. Not ideal for: An actual infestation with multiple spiders a day — you need prevention as well, not just removal.

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2. Spider Trap 12-Pack Sticky Indoor Glue Traps — £13.49

Flat, low-profile glue traps designed to sit against skirting boards, behind furniture, and under sinks — the routes a wandering male actually uses to move through a room. Because September’s spider problem is mostly about movement rather than nesting, this is often the single most effective product on this list for the exact situation most people are dealing with right now.

Pros: Cheap enough to place generously through the whole house, works passively with no spraying or scent, also catches other crawling insects.
Cons: Won’t catch a spider that’s web-building rather than walking, and finding a trapped spider isn’t pleasant if you’re squeamish.
Best for: Entry points — under doors, beside skirting boards, in utility rooms. Not ideal for: Homes with curious cats or toddlers who might pick one up; place these out of easy reach.

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3. Zero In Spider Repellent — Indoor Peppermint Oil Spray — £8.49

A non-toxic, peppermint-oil-based spray from a UK brand that’s been reliable across other categories we’ve reviewed (their fly and wasp products test consistently well too). Spiders dislike the scent and tend to avoid treated surfaces, which makes this more of a prevention tool than a kill-on-contact one.

Pros: Genuinely pleasant smell rather than a chemical one, safe to use around food-prep areas once dry, good for people who don’t want to kill spiders but do want fewer of them inside.
Cons: Needs reapplying every couple of weeks, does nothing for a spider already in the room with you right now.
Best for: Window sills, door frames, conservatory edges — anywhere spiders are getting in. Not ideal for: A false widow colony that needs actually clearing, not just deterring.

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4. CritterKill Spider Trap 30-Pack — £15.95

The bulk version of the glue trap approach, and worth it if you’re dealing with more than the odd spider — a loft conversion, a converted cellar, or a house that backs onto open fields where spiders have an easy route in. Thirty traps sounds excessive until you’ve actually tried covering every skirting board in a three-bed house.

Pros: Works out cheaper per trap than the 12-pack, covers a whole house properly rather than one room, catches other autumn invaders (silverfish, woodlice) as a side benefit.
Cons: Same limitation as any glue trap — passive, not instant, and unpleasant to dispose of if you’re squeamish.
Best for: Larger homes or a genuine multi-room problem. Not ideal for: A single spider in the bath — that’s a job for the catcher stick, not thirty traps.

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5. Karlsten Spider Killer Repellent Spray (High Strength) — £12.99

This is the one to reach for if you want an actual kill, not just a deterrent — a contact insecticide spray that also leaves a residual barrier. It’s the strongest option on this list, and the only one we’d flag as needing real care with handling.

Pros: Kills on contact rather than just repelling, residual effect means fewer repeat applications, works on false widows as well as harmless species.
Cons: Contains insecticide, so it’s not something to spray near food, fish tanks, or where pets and children can access it before it’s fully dry; needs a ventilated room while spraying.
Best for: A confirmed false widow sighting or a genuinely bad infestation. Not ideal for: Households wanting a chemical-free approach — pair the peppermint spray with the catcher stick instead.

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Step-by-Step: Using These Effectively

1. Deal with the spider in front of you first. If it’s just one and you don’t want it dead, use the catcher stick and release it outside, away from the house. Wear gloves if you’re not confident on identification.
2. Walk the perimeter of each ground-floor room and place glue traps against skirting boards, under sofas, behind wardrobes, and in utility rooms and cellars — anywhere dark, undisturbed, and close to a wall, which is how wandering males actually travel.
3. Spray the peppermint repellent around every entry point — door thresholds, window frames, air bricks, gaps around pipework. Reapply every 10–14 days through the peak September–October window.
4. If you’ve confirmed a false widow or a genuinely heavy infestation, use the Karlsten spray directly on the spider and the immediate area, in a ventilated room, wearing gloves, and keep pets and children out until it’s dry.
5. Declutter and seal. Spiders follow insect prey and hide in clutter — reducing cardboard boxes, clearing cobweb corners, and sealing obvious gaps around doors and utility pipes makes every product above work better and for longer.
6. Check and replace traps every 2–3 weeks through the season, and dispose of full ones in an outside bin rather than indoors.

Health and Safety: What’s Actually Worth Worrying About

Most UK house spiders are entirely harmless — of the 650 or so species recorded in Britain, only around 12 have ever been documented as able to bite a human, and for the vast majority of those, the bite is comparable to a mild nettle sting at worst.

The one genuine exception is the false widow (Steatoda nobilis), and the British Pest Control Association (BPCA) has published specific guidance on it because sightings have been rising across southern England in particular. BPCA’s position is measured rather than alarmist: false widows are not aggressive and will only bite if directly provoked or trapped against skin, and while the bite is venomous, it’s typically compared to a wasp sting — most of the medical concern around false widow bites actually comes from secondary skin infection afterwards, not the venom itself. If you’re stung, wash the area with soap and water, avoid scratching, and use an antihistamine for itching. Seek NHS advice if you notice spreading redness, swelling, or signs of infection, or if you have any signs of a more serious allergic reaction.

If you’re not confident identifying what’s in front of you, treat it as false widow-safe practice by default: don’t handle it bare-handed, use the catcher stick or a glass-and-card method instead, and wear gloves if you need to clear a web or nest by hand.

A quick word on look-alikes, because this comes up a lot: a false widow is often mistaken for a woodlouse spider (which has a distinctive reddish body and dark head, and is harmless) or simply a large, dark house spider. If you’re genuinely unsure, photograph it from a safe distance rather than approaching for a closer look, and treat any bite that starts swelling significantly, spreading, or feeling hot to the touch as a reason to get it checked rather than waiting it out.

It’s also worth saying plainly: a fear of spiders is extremely common and nothing to feel embarrassed about. A YouGov survey found that around 21% of Britons — an estimated 11 million people — describe themselves as having arachnophobia, and that number rises to almost half of 18–24 year-olds. If dealing with spiders yourself isn’t something you want to do at all, that’s a completely reasonable reason to call in help rather than a failure to “just get over it.”

When to Call a Professional

DIY products handle the vast majority of September’s spider spike perfectly well. It’s worth calling in a professional instead when you’re dealing with a confirmed false widow colony rather than a single spider, when an infestation is coming from somewhere you can’t safely access yourself (a loft void, wall cavity, or crawl space), or when the fear itself is the real problem and no amount of traps will make you feel comfortable handling it. Our pest control service page has more on what a professional visit typically involves and what it costs, if DIY isn’t cutting it or isn’t something you want to take on yourself.

Frequently Asked Questions

Why are there suddenly so many spiders in my house?
It’s mating season, not an invasion. From early September to mid-October, male house spiders leave their webs to search for females, which is why you’re seeing more of them moving around in the open rather than there being more spiders overall.

Are house spiders in the UK dangerous?
Almost never. Of roughly 650 UK spider species, only about 12 have ever been recorded biting a person, and most bites are harmless. The false widow is the main exception worth knowing how to identify.

Does peppermint oil actually repel spiders?
There’s decent anecdotal and some experimental support for spiders avoiding strong mint scents, though it’s not a guaranteed barrier — it works best as one layer of prevention alongside traps, not as a sole solution for a serious problem.

Do ultrasonic spider repellers actually work?
The evidence is weak. Spiders don’t have ears in the way insects that respond to ultrasonic devices do, so we’d treat any “ultrasonic spider repeller” claim with scepticism and stick to traps, sprays, and sealing entry points instead.

What’s the biggest spider I might find in a UK home?
The giant house spider (Eratigena atrica), with a leg span that can reach 7–8cm. It’s the one most likely to cause a fright, but it’s completely harmless and doesn’t bite defensively.

How do I get rid of a spider without killing it?
A catcher stick or the classic glass-and-piece-of-card method both work well — gently trap the spider, carry it outside, and release it away from the house.

UK Spider Activity: A Seasonal Calendar

Browse the Full Range

The five products above cover most households, but if you want to see everything in stock — more traps, more repellent formats, and a few specialist options — the full spider control range is worth a look. And if the problem’s bigger than DIY can handle, our pest control service page explains what professional help typically involves.

As an Amazon Associate, Pest Eliminator earns from qualifying purchases. We only recommend products we’d genuinely use ourselves, and every price and stock status in this article was checked at the time of publishing.

This guide was written based on our experience advising UK homeowners on spider control, cross-checked against British Pest Control Association guidance and current entomological research on UK house spider behaviour. Always wear gloves when handling traps or clearing webs, and keep chemical sprays away from children and pets until fully dry.

— Adam Jones, Pest Eliminator