The short version
Most spiders in Dover are harmless. Black widows live here, as in every lower-48 state. Dover 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 Dover 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.
- 1Spider activity in the garage near the door gap.
- 2Round or teardrop egg sacs tucked into eaves and window frames.
- 3Shed spider skins on windowsills and baseboards.
- 4Webs clustered around porch lights and windows.
- 5Tan spider with a violin mark and six eyes.
- 6Silk strands stretched across windows after wind.
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
A pro in Dover starts by walking the exterior, garage, basement and eaves with a flashlight, noting webs and where insects gather. The goal is to name the species before deciding anything.
- Time
- 45–90 minutes
- Best for
- Every job; the species decides how much to do
Monitoring and Follow-Up
$50–$150 per visit
A follow-up visit in Dover typically happens two to four weeks after treatment. The technician checks traps, rebrushes new webs and touches up dust.
- Time
- 20–45 minutes
- Best for
- Confirming results; recluse or widow properties
Sealing Gaps, Lighting and Prey Reduction
$150–$450
Bright white porch lights draw moths and midges, which draw spiders. Yellow bulbs away from doors make a real difference.
- Time
- 1–4 hours
- Best for
- Long-term reduction; homes near woods, water or fields
Exterior Perimeter Treatment and Void Dusting
$150–$350
Ask what product is used and why it fits your Dover situation. Labels vary, and the choice should be explained plainly.
- Time
- 45–120 minutes
- Best for
- Heavy exterior activity, widows or recluses confirmed
Prices are typical published ranges. Ask what’s included before you compare quotes.
Basements stay dark, damp and quiet, which is everything a spider wants.Which spiders live around Dover.
Most suspects turn out to be harmless look-alikes. Brown recluses don't live around Dover. Around Dover, they're northern black widows, usually hiding under decks, grills and meter covers. All are harmless to people. Most spiders in Dover homes are house spiders, cellar spiders, jumping spiders and wolf spiders.
Local spiders conditions in Dover.
A provider who works Dover 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 Dover'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 Dover usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Around Dover, 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. Dover 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 Dover 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 Dover have basements, and basements are spider central.
A year of spiders in Dover.
- Winter: with lows near 15°F in Dover, a good time to clear clutter and seal gaps. - Fall: males wander indoors. Peak spider season. - Summer: highs near 81°F in Dover 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
- Eave depth and roofline height.
- Season and how heavy current activity is.
- Wooded, wet or open-field surroundings.
- Exterior siding type and number of gaps.
- Whether outbuildings, sheds and decks are included.
- Inclusion of web and egg-sac removal.
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What's your biggest concern about spiders?
When to call for help
Call if a black widow is near where kids play. if spiders keep coming back after cleaning. High eaves and attics are worth leaving to a pro.
What you can do yourself
A pro adds targeted treatment in cracks and voids. They don't reach hiding spots. Skip foggers. Add door sweeps and store things in sealed bins. Switch to yellow bug lights. Start simple.
Spiders in Dover
With about 46 inches of rain a year and humidity near 69%, Dover supports plenty of insects, and spiders follow them. In Dover's neighborhoods, eaves, porch lights, woodpiles and garages are spider favorites. Dover has a humid continental climate, and spiders activity here tends to follow late summer through fall (August-October). An inspection in Dover that starts outside and works inward usually finds the entry points, moisture, and shelter that matter most before anyone treats.
Local research
Spiders in Dover, 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 Dover, and what the state figures look like. Everything below links to the agency or university page it came from.
When spiders are busiest around Dover
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 Dover’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
- Clear leaf litter and debris from foundations.
- Vacuum webs and egg sacs weekly during warm months.
- Keep garage doors closed and weatherstripped.
- Cover weep holes with fine mesh, not caulk.
- Wear gloves when handling outdoor furniture.
- Run a dehumidifier in damp basements.
Spiders found in a bathtub or vanity usually wandered in from a gap behind the plumbing, not up the drain.Did you know?
Jumping spiders see in color and plan their route before they pounce
Wolf spider mothers carry hundreds of spiderlings on their backs
Questions people ask
Will treatment get rid of all the spiders?
No, and that's fine. The goal is fewer spiders indoors. A few outside help control other pests.
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.
How long does spider treatment take to work?
You'll usually see fewer within a week or two. Webs and egg sacs need clearing too, or new spiders hatch.
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.
Do brown recluses live in my area?
Probably not. New Hampshire is outside the brown recluse range.
What is the most common spider found inside homes?
Bertone and colleagues, in their 2012 inspection of 50 North Carolina homes, found cellar spiders in 84% of houses, making them the most widespread spider family in the study. The useful next step in Dover is an inspection that pins down the source rather than a guess from national numbers.
What does a severe spider infestation cost to treat?
Local quotes vary; ask for a written estimate. As you collect quotes in Dover, ask each company what's typical on your street.
Are there dangerous spiders in Dover?
Black widows, yes, as almost everywhere. Most other spiders here are harmless.
When are spiders worst in Dover?
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