What kills spiders naturally?

Nothing needs to "kill" them for a real result — vacuuming up spiders, webs, and egg sacs, then removing their insect food supply and sealing entry points, is the extension-backed approach that reduces indoor spider activity (UMN Extension, Colorado State Extension). Dispose of the vacuum bag or canister contents promptly so nothing crawls back out, and repeat the process on a regular schedule rather than treating it as a single one-time cleanup, since new spiders can always wander in from outside.

Does peppermint oil repel spiders?

Marginally and briefly. A strong peppermint scent may cause a spider to detour for a short time, but it evaporates quickly and does nothing to spiders, webs, or egg sacs already established in the home. UC IPM notes that even insecticide sprays "don't provide good control anyway" outdoors, which puts a natural oil spray in even weaker territory — mechanical removal and exclusion are what actually work for a lasting result.

Do ultrasonic spider repellers work?

No reliable evidence supports them. A peer-reviewed study (Meehan, Pest Management Science, 1984) found no significant reduction in pest activity from ultrasonic devices, and later reviews replicate the finding across other pest categories as well. Spiders and other pests habituate to the sound quickly, and the waves don't meaningfully pass through walls or furniture anyway. Save the money for a vacuum hose extension and a tube of caulk instead.

Are the spiders in my house dangerous?

Almost certainly not. In most regions the only medically significant spiders are widow species, and even those bites are rare because spiders actively avoid people and only bite defensively when trapped against skin, per Colorado State and UC IPM. The vast majority of house spiders you'll actually encounter are completely harmless and are arguably beneficial, since they prey on other household insects like flies and moths.

Is natural spider control safe for pets?

Yes, with one specific caution — concentrated peppermint or clove essential oils sold as spider repellents are toxic to cats and dogs per the ASPCA, so avoid spraying them anywhere pets roam, sleep, or groom themselves. Vacuuming, web and egg-sac removal, sealing entry points, and switching exterior lighting carry no pet-safety concerns at all and are the methods that actually reduce spider activity.

How do I stop cobwebs from coming back?

Routine vacuuming or dusting of undisturbed corners, combined with reducing the indoor insect population that spiders are hunting in the first place, keeps cobwebs from reaccumulating, per Oregon State University Extension. This is genuinely ongoing maintenance rather than a one-time fix — corners that go unchecked for weeks will collect webs again, so build it into a regular cleaning routine instead of expecting permanent eradication.

Why do I see more spiders in the fall?

As outdoor temperatures cool, wandering male spiders move indoors seeking shelter and mates — a well-documented seasonal pattern noted by UMN Extension that has nothing to do with anything a homeowner did wrong. Sealing cracks and gaps around the foundation and ground-level windows before New Hampshire's first hard frost, roughly mid-to-late October in Manchester, is the most effective natural response to this predictable annual spike.

Do fogger or spray pesticides work on spiders outdoors?

No — UMN Extension notes surface treatments and foggers are not effective against spiders outdoors, and UC IPM makes the same point about insecticides generally in this context. Spiders often aren't in direct, prolonged contact with treated surfaces the way crawling insects like ants are, which is a large part of why mechanical removal and exclusion consistently outperform spraying for this particular pest group.

Does reducing outdoor lighting really help?

Yes — this is one of the few "lifestyle" tips with genuine evidence behind it rather than folk wisdom. Bright white porch and exterior lights attract flying insects at night, and spiders simply follow that reliable food supply to wherever the insects gather. Switching to yellow "bug" bulbs or redirecting lights away from doors and windows measurably reduces the insect draw and, in turn, the spider activity that depends on it (UMN Extension).

How long until I see fewer spiders?

Mechanical removal — vacuuming up spiders, webs, and egg sacs — gives an immediate, visible reduction the same day you do it. The ongoing benefits from exclusion and lighting changes build more gradually over several weeks, as fewer insects, and therefore fewer spiders hunting them, find their way inside. There's no single treatment that produces a permanent, one-time fix; expect to maintain the routine.

Natural & OrganicSpiders

Natural Spider Control: What Actually Works in New Hampshire

TL;DR

Mechanical removal rates MODERATE-to-HIGH — vacuuming spiders and egg sacs, sealing entry points, and reducing the insect prey that draws them genuinely cuts indoor spider activity. Peppermint sprays and ultrasonic repellers rate LOW to MYTH: they give brief or no real control. Most spiders are also harmless and beneficial, so the goal is management, not eradication.

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NH License #782664Family-owned since 2017Updated Jul 2026

What makes a spider a spider
8 legs and 2 body regions, versus an insect's 6 legs and 3 body regions
Colorado State University Extension
Realistic bite risk
In most regions the only medically significant spiders are widow species, and bites are rare because spiders avoid people
UC IPM / Colorado State Extension
Lighting as a real control lever
Reducing outdoor lighting cuts the insect prey that draws spiders to a home
UMN Extension — a documented lever, not a folk tip
Ultrasonic repellers
No reliable evidence of reducing spider or other pest activity
Peer-reviewed: Meehan, Pest Management (formerly Pesticide) Science, 1984; later reviews replicate the pattern

The honest verdict

Does this actually work?

MODERATE-to-HIGH for vacuuming/web removal plus exclusion and lighting changes; LOW for peppermint or essential-oil sprays as a standalone fix; MYTH for ultrasonic repellers.

Works — Moderate

Evidence: UMN and Colorado State Extension recommend capture-and-remove, web/egg-sac destruction, exclusion, and reducing outdoor lighting as the durable approach; UC IPM states insecticides "don't provide good control anyway" outdoors. A peer-reviewed study (Meehan, 1984) found ultrasonic devices produce no significant reduction in pest activity.

Works when

Spiders, webs, and egg sacs are vacuumed and removed regularly
Outdoor lighting is reduced or switched to less insect-attractive bulbs
Cracks and gaps around the foundation and ground-level windows are sealed
Clutter (boxes, woodpiles) that provides harborage is reduced

Fails when

You rely on peppermint spray or a plug-in ultrasonic device as the primary method
Egg sacs are left in place — each one hatches dozens of new spiders
Bright white exterior lighting keeps attracting insect prey
Fogging or surface pesticide sprays are used outdoors instead of removal

At a glance

Skip the peppermint spray — here's the natural spider control that actually reduces activity

How it works

Easy DIY

Natural spider control is mechanical, not chemical: physically remove spiders, webs, and egg sacs; reduce the insect prey that draws them in with lighting changes and general pest reduction; and seal the cracks and gaps they use to get inside. It works because it addresses the two things a spider actually responds to — available prey and available entry — rather than a scent it can simply route around.

Vital stats

Time: Ongoing — weekly vacuuming with visible results immediately; exclusion benefits build over weeks
Best for: Common/American house spiders, cellar spiders, and other cobweb-building species in basements, garages, and undisturbed corners of a New Hampshire home.
Cost: Low — a vacuum you likely already own, caulk, and inexpensive bulb swaps

"Does peppermint oil get rid of spiders" is one of the most-searched spider questions, and the honest answer is: barely, and briefly. A spider that wanders through a puddle of peppermint scent might turn around for a few minutes, but the scent fades fast, and it does nothing about the spiders, webs, and egg sacs already established in your basement, garage, or eaves.

The good news is the method that genuinely works is simple and doesn't require buying anything exotic: vacuum up spiders, webs, and egg sacs; cut off their food supply by reducing outdoor lighting and other insects; and seal the cracks they're using to get inside. It's also worth a reality check most pest content skips — the overwhelming majority of spiders in and around a New Hampshire home are harmless and beneficial predators of other insects. This page grades the popular remedies honestly and walks through the extension-backed protocol that actually reduces spider activity.

Step by step

How to do it

Vacuum spiders, webs, and egg sacs
Use a vacuum with a hose attachment to remove spiders, webs, and egg sacs from corners, eaves, and undisturbed areas. Dispose of the bag or canister contents promptly.
Tip: An extension hose reaches high eaves and ceiling corners safely without a ladder.
Reduce clutter
Clear boxes, bags, and woodpiles from basements, garages, and closets — these are prime spider harborage because they're undisturbed and hold insect prey.
Tip: Elevate storage off the floor and away from walls when possible.
Seal cracks and gaps
Caulk cracks around the foundation, doors, and ground-level windows where spiders and their insect prey get inside.
Caution: Focus on ground-level and basement gaps first — that's where most indoor spider entry happens.
Switch exterior lighting
Replace bright white porch and exterior bulbs with yellow "bug" bulbs, or redirect lights away from doors and windows to reduce the insects that draw spiders.
Tip: This single change measurably cuts the food supply that keeps spiders coming back.
Trim vegetation touching the house
Cut back shrubs and branches that touch siding or windows — they act as a bridge for spiders and their insect prey to reach the structure.
Tip: Keep a gap of a foot or more between foliage and exterior walls.
Knock down outdoor cobwebs
Use a broom or hose to knock down cobwebs on eaves, porches, and outdoor fixtures regularly, before they become established egg-laying sites.
Tip: Do this on a routine schedule rather than only when webs become visible.

What you need

Tools & materials

Vacuum with hose attachment
Physical removal of spiders, webs, and egg sacs
Dispose of the bag/canister contents promptly
Caulk or sealant
Exclusion at the foundation, doors, and ground-level windows
Wear gloves; focus on ground-level gaps
Yellow "bug" LED bulbs
Reduce insect prey that draws spiders to the exterior
A documented, evidence-backed lever, not a folk tip
Broom or duster
Routine web removal on porches and eaves
Use on a regular schedule

Products & actives

What to use — the label is the law

Product classes only — never a dosage. Always read and follow the product label.

Food-grade diatomaceous earth

Active class: Amorphous silica (desiccant)

Dry application in cracks and voids near known entry points

Food-grade only; apply dry; wear a dust mask

Sticky monitoring traps

Active class: Adhesive (glue board)

Monitoring spider activity in basements and garages

Place out of reach of pets — can catch fur or curious paws

25(b) minimum-risk essential-oil sprays

Active class: Peppermint or clove oil

Brief contact-kill/repellent on individual spiders — not infestation control

Contact-kill only, short-lived; read and follow the label

Stay safe

Safety first

Pets
Caution
Concentrated peppermint and clove essential-oil sprays are toxic to cats and dogs per the ASPCA — avoid using them where pets roam or sleep.
General
Low risk
Don't reach blindly into dark corners, woodpiles, or storage boxes — a reasonable precaution given widow spiders are the one group with medically significant bites.
General
Low risk
Food-grade diatomaceous earth is a fine silica dust — apply dry only and wear a dust mask to avoid inhaling it.
Pets
Low risk
Sticky monitoring traps can catch a curious pet's fur or paw — place them where pets can't reach.

Avoid these

Common mistakes

Why this method fails in practice.

Spraying baseboards with essential oils instead of physically removing webs and egg sacs
Leaving egg sacs in place — each one can hatch dozens of new spiders
Leaving bright white porch lights on, which attracts the insect prey spiders follow
Relying on a plug-in ultrasonic repeller instead of vacuuming and sealing
Fogging or spraying outdoors expecting broad control that extension sources say doesn't work

New Hampshire context

Natural spider control in New Hampshire

New Hampshire homes near fields, rivers, and lakes tend to see more spiders simply because they have more insect prey nearby, following the same pattern UMN Extension documents for the broader region. "Spider season" in fall — when wandering male spiders move indoors seeking mates and shelter as temperatures drop — is the predictable seasonal spike homeowners notice most. Sealing up before the first hard frost (roughly October 19–29 in Manchester, per NOAA) is the natural-control move that pays off before that fall influx rather than after.

Peak season

Fall, as cooling temperatures push wandering spiders indoors

First-frost anchor: Manchester first hard frost ~Oct 19 (50%) / Oct 29 (80%) per NOAA 1991–2020

Vacuuming, web removal, exclusion, and lighting changes are DIY-legal statewide; no pesticide license needed for these non-chemical methods.

Regional extension guidance (UMN, Colorado State, UC IPM) consistently frames spiders as beneficial predators best managed through mechanical removal and exclusion rather than broad pesticide use.

This method targets

Pests this applies to

When to call a pro

Spider Pest Control with Anchor

Vacuuming, exclusion, and lighting changes handle the overwhelming majority of household spider activity, and most spiders you'll see are harmless. But recurring heavy webbing, a suspected widow spider, or activity near play areas or a bedroom outpaces what most homeowners want to manage themselves — Anchor's licensed technicians treat harborage and entry points and knock down the insect prey base directly.

Call us when…

Recurring heavy webbing returns within days of a thorough cleanup
A suspected black widow or other medically significant spider is present
Spider activity is concentrated near a child's play area or a bedroom
The infestation source (a large insect population) can't be identified or controlled
You want an ongoing exterior treatment program rather than manual upkeep

Spider Pest Control

free inspection; same-day service across southern and central New Hampshire.

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Keep them out

Keep exterior lighting low or switched to yellow bug bulbs
Seal ground-level and foundation gaps before New Hampshire's fall spider influx
Reduce clutter in basements, garages, and closets where spiders and prey harbor

Common questions

Frequently asked

Sources & further reading(6)

[1]
University of Minnesota Extension — Spiders
Mechanical removal, lighting as a control lever, fall indoor movement, foggers ineffective
extensionverified 2026-07-13
[2]
Colorado State University Extension — Spiders in and around the Home
8 legs/2 body regions, widow spiders as the only medically significant risk, bites rare
extensionverified 2026-07-13
[3]
UC IPM — Cobwebs Everywhere
Insecticides don't provide good outdoor control; mechanical removal preferred
extensionverified 2026-07-13
[4]
Oregon State University Extension — What are all these webs showing inside my house?
Routine vacuuming/dusting manages cobwebs; realistic control-not-eradication framing
extensionverified 2026-07-13
[5]
Pest Control Insider — Do ultrasonic pest repellers work?
Summary of the Meehan (1984) peer-reviewed finding that pests habituate to ultrasonic devices
industryverified 2026-07-13
[6]
ASPCA — Essential oils and pets
Peppermint and clove oil toxicity in cats and dogs
medicalverified 2026-07-13

Written & reviewed by

Verified

Daniel Brady

NH-Licensed Pesticide Applicator · License #782664 (NHDAMF, RSA 430)

Daniel Brady is the New Hampshire–licensed applicator behind Anchor Pest Services, a family-owned pest control company serving the Manchester area since 2017.

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Anchor Pest Services

When spiders won't quit, we will.

Same-day service across Southern New Hampshire. NH-licensed #782664. Family-owned since 2017. We diagnose the pest, then treat it the right way — with a satisfaction guarantee.

Get a free inspection Call (603) 785-0118

Keep Exploring

Natural Spider Control: What Actually Works in New Hampshire

Works when

Fails when

Skip the peppermint spray — here's the natural spider control that actually reduces activity

How it works

How to do it

Vacuum spiders, webs, and egg sacs

Reduce clutter

Seal cracks and gaps

Switch exterior lighting

Trim vegetation touching the house

Knock down outdoor cobwebs