The short version
Around Westminster, queens start nests in May, and colonies peak in late summer. Small, low paper wasp nests can be handled at dusk. Leave wall, ground and high nests to a pro.
- Treat nests at dusk, when wasps are home.
- Never seal a hole wasps are using.
- Ground and wall nests are best left to a pro.
- Knock down small nests early in spring.
- Call 911 for breathing trouble after a sting.
Anyone in Westminster dealing with wasps, hornets or yellowjackets at home.
What to look for
Late-summer colonies are big and quick to sting. Near a door or deck, stings will happen. Wasps defend the area around their nest.
- 1Dead wasps collecting on interior windowsills in late summer.
- 2Yellowjackets crowding trash cans, soda cans and pet food.
- 3Open umbrella-shaped comb under a porch ceiling or railing.
- 4Small golf-ball-sized paper nests under eaves in spring.
- 5Wasps entering an attic vent, dryer vent or weep hole.
- 6Large wasps circling porch lights after dark.
Why it’s worth acting soon
- Nests grow all summer.
- Ground nests get disturbed by mowing.
- Wall nests can chew through into rooms.
- Stings are dangerous for anyone allergic.
Treatment options and typical costs
Inspection and Nest Identification
$75–$200
The inspection also flags anyone in the Westminster household with a sting allergy, which changes how and when the work gets done. Ask for photos of what was found.
- Time
- 45–75 minutes
- Best for
- Every job; species and nest location decide the method
Sealing Up After the Nest Is Dead
$150–$450
This is the step homeowners skip most often. Sealing the void after treatment keeps the next colony out.
- Time
- 1–2 hours
- Best for
- Sealing the gap once the nest is dead
Ground and Wall-Void Nest Treatment
$150–$500
Ground nests can hold thousands of yellowjackets by late summer. Mowing over one sets them off. Treatment is done in protective gear, usually at dusk.
- Time
- 30–60 minutes plus a return visit
- Best for
- Yellowjackets in lawns, retaining walls, soffits and wall voids
Aerial Nest Treatment and Removal
$100–$400
Exposed paper wasp and hornet nests under eaves, in trees or on porch ceilings in Westminster are treated with a fast-acting aerosol or dust, then removed once the colony is dead. Most are handled in a single visit.
- Time
- 30–90 minutes
- Best for
- Exposed paper wasp, hornet and bald-faced hornet nests
Prices are typical published ranges. Ask what’s included before you compare quotes.
Once a nest is dead, screening and sealing gaps around pipes and vents keeps next year's queen from using the same opening.Which wasps live around Westminster.
Paper wasps are the most common around Westminster. They build open, umbrella-shaped combs under eaves and railings. Western yellowjackets nest in the ground and in wall voids. They cause most stings. Bald-faced hornets build big gray nests in trees and eaves. Mud daubers build tube-shaped mud nests. They rarely sting.
Local wasps conditions in Westminster.
Westminster sits in a semi-arid climate, and that sets the pace for wasp activity here: mid-summer through fall (July-October). In Westminster, the area is mostly suburban, so wasps 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. An inspection in Westminster usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Knowing Westminster'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. A provider who works Westminster and Colorado 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.
Yellowjackets sometimes nest in attics and wall voids, getting in through a torn vent screen or a gap in the soffit. Buzzing in a ceiling is worth a look.When they’re most active.
Nests die back after the first hard freeze in fall. Early spring is the easiest time to remove small starts.
Where they nest around houses here.
Plenty of homes in Westminster have basements, but most nests are higher up. Check eaves, attic vents and window frames. Watch for traffic in and out of gaps. A ground nest looks like wasps streaming from one hole. Homes from Westminster out to Arvada and Thornton share the same favorite nest spots.
A year of wasps in Westminster.
- Spring: queens start new nests around May. Knock down small starts. - Summer: highs near 89°F in Westminster help colonies grow fast. - Late summer: peak season. Workers hunt sweets near people. - Winter: lows near 19°F in Westminster. Nests die; only queens survive.
Wasp, hornet or bee?
- Paper wasp: slim, long legs, open comb. - Yellowjacket: bright yellow and black, nests in the ground. - Hornet: larger, with a big closed paper nest. - Mud dauber: thin waist, mud tube nests. Rarely stings. - Honey bee: fuzzy and golden. about relocation.
If you get stung.
Move away from the nest first. Wash the sting and use a cold pack. An antihistamine can ease itching and swelling. 911 for trouble breathing or a swollen face or throat. If someone carries an epinephrine pen, use it.
Keeping wasps away from the patio.
- Food: cover plates and drinks outdoors. - Trash: keep lids tight and bins away from doors. - Fruit: pick up fallen fruit. - Spring checks: knock down small nests early. - Gaps: seal gaps after a nest is gone.
Ground nests: what to do.
Mark the hole with a flag. Keep kids and pets away. Don't mow over it. Don't pour gasoline or water in. Pros treat ground nests at night, when the colony is home.
A nest, or just visitors?
Wasps on flowers or trash cans may come from far away. A nest shows steady traffic to one spot. Watch at dusk, when they fly home. Follow the line back to an eave, vent, shrub or hole.
Treating a small nest yourself, safely.
- Only if it’s small, low and out in the open. - Never if anyone in the house is allergic. - Wait until dusk, when wasps are home and slow. - Wear long sleeves, pants and gloves. - Use a jet wasp spray from several feet away. - Never spray from a ladder. - Leave it overnight, then bag the nest.
Wasps and pets.
Dogs often snap at wasps and get stung on the face. Most stings just swell a little. your vet if the throat swells or breathing changes. Keep pet food and water bowls indoors in late summer.
Kids and wasps.
Teach kids to walk away calmly. Swatting makes a sting more likely. Check play sets, slides and playhouses for nests each spring. Use cups with lids for sweet drinks outside.
After the nest is gone.
Wasps don't reuse old nests. Seal the gap a wall nest used once it's quiet. Check nearby eaves for new starts. Knock down small new nests early next spring.
Wasps at picnics and barbecues.
- Drinks: use cups with lids or straws. - Food: keep it covered until you eat. - Trash: bag scraps and close the bin. - Calm: don’t swat; slowly move away. - Kids: teach them to walk away calmly.
Ground nests in the lawn.
Yellowjackets often nest in old rodent holes. Watch for wasps flying in and out of the grass. Mark it, and keep mowers and kids away until it's treated.
Questions to ask before you sign.
- What kind of wasp is it? - How will you treat a nest inside the wall? - Is removal of the dead nest included? - Is a return visit included?
What affects the price
- Ground nest with multiple entrances or deep burrows.
- Sealing gaps after the nest is dead.
- Species: paper wasps cost least, hornets and yellowjackets more.
- Return visit to confirm a void nest is dead.
- Nest height and whether a ladder or lift is needed.
- An open comb or a nest inside a wall.
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What's your biggest concern about wasps?
When to call for help
Call for nests in walls, attics, the ground, or anywhere high. right away if anyone in the house is allergic. Don't seal a hole wasps are using. They'll find another way in.
What you can do yourself
A small, reachable paper wasp nest is a fair DIY job. Spray it at dusk with a wasp aerosol. Knock it down the next day. Big, high or hidden nests are a job for a pro.
Wasps in Westminster
Westminster only gets about 16 inches of rain a year, so local wasps often gather at pools, fountains and dripping taps. Winter lows near 19°F in Westminster end the season; only new queens survive, tucked into sheltered spots. In Westminster's neighborhoods, eaves, decks, play sets and shrubs are favorite nest sites.
Local research
Wasps in Westminster, CO: what the public record shows
Before you compare quotes, it helps to know which wasps actually live in Colorado, when they are busiest around Westminster, and what the state figures look like. Everything below links to the agency or university page it came from.
Wasp species recorded in Colorado
- Western yellowjacket (Vespula pensylvanica) — UC IPM: 'the most commonly encountered species and is sometimes called the "meat bee"' in California and the Western states; ground and wall-void nester and aggressive scavenger…
- Bald-faced hornet (Dolichovespula maculata) — Penn State: 'found in most of the 48 contiguous states and D.C., throughout Canada and in Alaska'; actually an aerial yellowjacket that builds the football-shaped gray paper nes…
- European paper wasp (Polistes dominula) — Penn State: 'first reported in 1978 around Boston', now 'coast to coast ... although they are apparently less common in the Southeast and Great Plains'; nests in 'eaves of struc…
- Native paper wasps (Polistes spp. (e.g., P. fuscatus, P. apachus, P. exclamans)) — Open umbrella-shaped nests under eaves, porch ceilings and railings. UC IPM: paper wasp colonies 'vary between 15 to 200 individuals'; Penn State: queens 'establish nests in May…
When wasps are busiest around Westminster
CSU: European paper wasp 'earliest activity is sometimes seen in the first half of March'; 'Individual colonies are established anew each spring' and 'may contain several dozen individuals by the end of summer'. Western yellowjacket colonies die each fall (USU).
CSU: European paper wasp is 'very abundant in every urbanized county in eastern Colorado and the three western Colorado counties of Mesa, Montrose, and Delta'; nests in 'outdoor grills, large bells, pipes, rock cavities, and hollow spaces behind walls'.
Rules that apply in Colorado
For context, nationally
- 788 — Deaths from hornet, wasp, and bee stings, 2011–2021 (US). CDC MMWR
- 72 deaths per year — Average annual sting deaths, 2011–2021 (US). CDC MMWR
Sources: Colorado State University Extension; CDC MMWR; Yellowjackets and Other Social Wasps (Pest Notes); Baldfaced Hornet; European Paper Wasp. Figures are quoted as the source prints them. How we check our sources
Simple ways to keep wasps away
- Inspect grills, mailboxes and light fixtures before use.
- Clean outdoor eating areas right after meals.
- Keep trash cans lidded and rinse recycling before binning.
- Caulk around cable, gas and conduit entry points.
- Screen attic, gable and dryer vents with fine mesh.
- Plug weep holes with mesh inserts, not solid caulk.
Jot down where nests turned up this year. Queens often pick the same eaves and gaps, so you'll know where to look first next spring.Did you know?
Wasp nest paper inspired early experiments in making paper from wood
Yellowjacket nests are never reused a second year
Questions people ask
What time of day should a wasp nest be treated?
At dusk or after dark, when they're home and calm.
What should I do if I get stung?
An antihistamine helps with itching. 911 for trouble breathing or a swelling throat.
Why are there suddenly so many wasps in late summer?
Colonies are at their biggest by late summer. Food gets scarce, so workers hunt sweets and protein near people.
Wasp or bee: does it matter?
Wasps are smooth and narrow-waisted. Bees are fuzzy and rounder. It matters because honey bees can often be relocated.
How do I know if I have wasps, hornets or yellowjackets?
Paper wasps build open, umbrella-shaped combs. Yellowjackets nest in the ground or walls. Hornets build big, gray, closed nests.
What stops people from dealing with wasp nests?
In Westminster, fear of stings, nests that are hard to reach, and not noticing them until they're big.
How often should you check your property for wasp nests?
Every week or two from spring through late summer. In Westminster, look under eaves, decks, sheds and play equipment, where small nests are easy to deal with.
When is wasp season in Westminster?
Around Westminster, queens start nests in May, and colonies peak in late summer. Nests die back after the first hard freeze in fall.
Are hornets common in Westminster?
Bald-faced hornets are, in trees and on eaves. Most stings come from yellowjackets, though.
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Sources (9)
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 Wasp Exterminator · Updated September 11, 2026 · How we write these guides