The short version
Most spiders in Londonderry are harmless. Black widows live here, as in every lower-48 state. Londonderry is outside the brown recluse range, so most 'recluses' here are look-alikes. Identify first, then treat.
- Most house spiders are harmless.
- Black widows live in every lower-48 state.
- Brown recluses don’t live here.
- Skip foggers; they don’t reach hiding spots.
- Yellow bug lights and door sweeps help a lot.
Homeowners and renters in Londonderry who'd like fewer spiders, and peace of mind about the dangerous ones.
What to look for
Webs and egg sacs keep the cycle going. Most are harmless and even helpful. More insects means more spiders. Spiders follow their food.
- 1Egg sacs, round or teardrop-shaped, tucked in eaves and frames.
- 2Spiders in a damp basement or crawl space.
- 3Spiders wandering across walls at night.
- 4Webs clustered around porch lights and windows.
- 5Webs behind shutters, meter boxes and utility panels.
- 6Shed spider skins on windowsills and baseboards.
Why it’s worth acting soon
- Egg sacs hatch hundreds of spiderlings.
- Webs build up in eaves, corners and garages.
- Widows nest under outdoor furniture and grills.
Treatment options and typical costs
Inspection and Species Identification
$75–$200
The inspection maps webs, entry cracks and what the spiders eat. Everything that follows is built on that map.
- Time
- 45–90 minutes
- Best for
- Every job; the species decides how much to do
Exterior Perimeter Treatment and Void Dusting
$150–$350
Ask what product is used and why it fits your Londonderry situation. Labels vary, and the choice should be explained plainly.
- Time
- 45–120 minutes
- Best for
- Heavy exterior activity, widows or recluses confirmed
Monitoring and Follow-Up
$50–$150 per visit
For homes in Londonderry where a brown recluse was confirmed, monitoring runs longer, because that species hides deep in stored items and emerges slowly.
- Time
- 20–45 minutes
- Best for
- Confirming results; recluse or widow properties
Sealing Gaps, Lighting and Prey Reduction
$150–$450
Firewood, lumber and dense shrubs by the foundation shelter spiders. Moving them out removes shelter and its insect food supply.
- Time
- 1–4 hours
- Best for
- Long-term reduction; homes near woods, water or fields
Prices are typical published ranges. Ask what’s included before you compare quotes.
Crawl spaces and their vents are worth a look with a flashlight, especially if a widow has turned up outside.Which spiders live around Londonderry.
Most suspects turn out to be harmless look-alikes. Brown recluses don't live around Londonderry. Around Londonderry, they're northern black widows, usually hiding under decks, grills and meter covers. All are harmless to people. Most spiders in Londonderry homes are house spiders, cellar spiders, jumping spiders and wolf spiders.
Local spiders conditions in Londonderry.
A provider who works Londonderry and New Hampshire every day can point out the specific conditions that matter most here, and getting the scope, price, and follow-up terms in writing makes it easier to compare options. Knowing Londonderry's seasonal timing lets you schedule treatment before the busy stretch rather than after it, which usually means faster service and a more accurate quote. An inspection in Londonderry usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Around Londonderry, the area is mostly suburban, so spiders pressure can differ from one block to the next depending on how tight the entry points are and how much food, water, or shelter is close by. Londonderry sits in a humid continental climate, and that sets the pace for spider activity here: late summer through fall (August-October).
Leaf piles against the foundation are prime fall shelter for spiders looking for a way inside.When you’ll see more of them.
Clear egg sacs in winter. Spring brings a new hatch. Winter lows around 15°F in Londonderry slow spiders outside, but house spiders carry on indoors. That's when males wander. You'll see the most in late summer and fall.
Where they hide in houses here.
Clutter gives them endless hiding spots. Check window wells, storage areas and the sill plate. Plenty of homes in Londonderry have basements, and basements are spider central.
A year of spiders in Londonderry.
- Winter: with lows near 15°F in Londonderry, a good time to clear clutter and seal gaps. - Fall: males wander indoors. Peak spider season. - Summer: highs near 82°F in Londonderry bring more insects, and more spiders. - Spring: new spiderlings hatch. Vacuum webs and egg sacs.
Harmless or worth a closer look?
- Orb weaver: big round web outside. Harmless. - Jumping spider: small, fuzzy, hops. Harmless. - Cellar spider: tiny body, very long legs. Harmless. - Wolf spider: big, hairy and fast. Harmless. - Brown recluse: tan, violin mark on its back, plain legs. - Black widow: shiny black, red hourglass underneath. Leave it alone.
If you think you’ve been bitten.
If you can, safely catch the spider for identification. See a doctor for severe pain, cramping or spreading redness. Raise the area if you can. Use a cool compress. Wash the bite with soap and water.
Fewer spiders, the easy way.
- Beds: keep them a few inches from the wall. - Shoes and gloves: shake them out before use. - Webs: vacuum webs and egg sacs every few weeks. - Clutter: store things in sealed plastic bins, not cardboard. - Gaps: add door sweeps and repair screens. - Lights: yellow bug lights draw fewer insects.
Webs outside: leave some, clear some.
- Gloves: wear them when moving firewood, pots or patio cushions. - Woodpiles: keep them off the ground and away from the house. - Eaves and window frames: a long-handled brush works well. - Doorways and porch lights: brush webs away weekly. - Garden orb weavers: leave them. They catch flies and mosquitoes.
Spider myths.
- Every blister is a recluse bite: most aren’t spider bites. - Spiders move in for winter: most house spiders never leave. - Daddy longlegs are deadly: no. They’re harmless. - Swallowing spiders in your sleep: no evidence it happens.
Spiders and pets.
Ask the company which products are cat-safe. Some sprays are risky for cats. your vet. A widow bite can sicken a dog or cat. Most spiders are no threat to pets.
What a spider visit looks like.
Inside, they focus on corners, closets and the garage. They treat cracks, gaps and hiding spots, not open lawn. They knock down webs and egg sacs around eaves and windows. The tech walks the outside first. Most visits take about an hour.
Sticky traps tell you a lot.
They show which spiders you have and where they travel. Check them after a week. Set sticky traps along baseboards, behind furniture and in the garage.
Outdoor lights and spiders.
Motion-sensor lights help too. Yellow bulbs attract fewer bugs. Porch lights draw insects, and insects draw spiders.
Cellar spiders in the basement.
A dehumidifier and a broom keep them in check. They're harmless and even eat other spiders. Long-legged cellar spiders hang in basement corners.
Spiders in the garage.
A door sweep and a sticky trap by the door help. Store things in sealed bins off the floor. Garages collect webs, boxes and insects.
Questions to ask before you sign.
- When can kids and pets go back in? - What happens if they come back? - Will you seal gaps or add door sweeps? - Is web and egg-sac removal included? - Where will you treat, inside and out? - Which spiders did you find?
What affects the price
- Crawl space or basement access and moisture.
- Season and how heavy current activity is.
- Eave depth and roofline height.
- Number of follow-up visits included.
- Door sweeps, screens and sealing work.
- Bundling with an existing general pest plan.
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What's your biggest concern about spiders?
When to call for help
High eaves and attics are worth leaving to a pro. if spiders keep coming back after cleaning. Call if a black widow is near where kids play.
What you can do yourself
Start simple. Switch to yellow bug lights. Add door sweeps and store things in sealed bins. Skip foggers. They don't reach hiding spots. A pro adds targeted treatment in cracks and voids.
Spiders in Londonderry
With about 44 inches of rain a year and humidity near 68%, Londonderry supports plenty of insects, and spiders follow them. In Londonderry's neighborhoods, eaves, porch lights, woodpiles and garages are spider favorites. Londonderry has a humid continental climate, and spiders activity here tends to follow late summer through fall (August-October). An inspection in Londonderry that starts outside and works inward usually finds the entry points, moisture, and shelter that matter most before anyone treats.
Local research
Spiders in Londonderry, NH: what the public record shows
Before you compare quotes, it helps to know which spiders actually live in New Hampshire, when they are busiest around Londonderry, and what the state figures look like. Everything below links to the agency or university page it came from.
When spiders are busiest around Londonderry
Late summer–early fall. Hunting spiders 'may enter into homes accidentally, particularly in the fall' and 'do not survive well indoors and usually do not reproduce indoors'. 'Funnel web spiders are the most common spiders found in homes, particularly during late summer and early fall'. 'The brown recluse (Loxoceles reclusa) is rare in Colorado because of our cold winters and dry climate' (same source), and 'Neither black widow spiders or brown recluse are native to the upper Midwest and are rarely encountered' (UMN). Cobweb and cellar spiders persist indoors year-round.
Based on Londonderry’s humid continental climate profile.
For context, nationally
- Throughout North America, but are most common in the southern and western United States — Black widow distribution. CDC/NIOSH
- In the midwestern and southern United States — Brown recluse distribution. CDC/NIOSH
Sources: CDC/NIOSH. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep spiders away
- Vacuum webs and egg sacs weekly during warm months.
- Clear leaf litter and debris from foundations.
- Wear gloves when handling outdoor furniture.
- Inspect items brought in from sheds and garages.
- Switch porch bulbs to warm or yellow LEDs.
- Control flies, gnats and other indoor insects.
Monitors along baseboards show whether spider numbers are actually falling after treatment.Did you know?
Spiderlings travel miles by ballooning on silk threads
Some spiders can survive months without a meal
Questions people ask
Do brown recluses live in my area?
Probably not. New Hampshire is outside the brown recluse range.
How do I choose a spider control company?
Check that they're licensed in New Hampshire. Ask them to identify the spiders before treating. Ask what's included and what happens if they come back.
Is spider treatment safe for pets and children?
Applied by the label, yes. Keep kids and pets away until treated areas dry. Ask what product they'll use.
Can I just leave the spiders alone?
Most house spiders are harmless and eat other pests. Widows are the exception, so check under outdoor furniture.
Is a spider bite what I think it is?
Often not. Many 'spider bites' are really other insects or skin infections. See a doctor if a bite spreads, blisters or hurts badly.
What is the most common spider found inside homes?
Around Londonderry, eighty-four percent of 50 North Carolina homes in a 2012 study contained cellar spiders, the long-legged web builders often mistaken for daddy longlegs. A good pro in Londonderry will explain how their plan fits what they found at your home.
Was it really a spider bite?
Probably not. Three point eight percent of the 182 patients who came to one California emergency department with a suspected spider bite between 2006 and 2007 actually received a spider-bite diagnosis, according to Suchard's 2011 clinical study. When you get quotes in Londonderry, ask each company what they usually see in your neighborhood.
Are there dangerous spiders in Londonderry?
Black widows, yes, as almost everywhere. Most other spiders here are harmless.
When are spiders worst in Londonderry?
Late summer and fall, when males wander.
Nearby cities
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Sources (12)
The facts in this article come from the public sources listed above. Every home is different, so ask the company you talk to about pricing and what’s included. Published by Spider Exterminator · Updated September 11, 2026 · How we write these guides