The short version
Around Olympia, flies are busiest from about May through September. Find their source: trash, drains, compost or a dead animal. Remove it, then seal gaps and screens.
- Flies breed in something nearby.
- Check trash, drains and compost first.
- Tape a drain overnight to test it.
- Big shiny flies can mean a dead animal.
- Screens and door sweeps keep them out.
Homeowners, renters and small businesses in Olympia dealing with flies.
What to look for
Spraying the flies you see won't stop new ones. In summer heat, eggs become adults in about a week. They breed in something nearby. Flies don't come from nowhere.
- 1Flies gathering at sunny windows.
- 2Tiny fuzzy flies near sinks and drains.
- 3Shiny green or blue flies indoors.
- 4Maggots in trash bins.
- 5Flies around compost or pet waste.
- 6A sudden bad smell with flies.
Why it’s worth acting soon
- Flies carry germs onto food and counters.
- Populations grow fast in warm weather.
- A dead animal smell gets worse.
- Cluster flies return every fall.
Treatment options and typical costs
Source Inspection and Fly Identification
$75–$200
Expect a pro in Olympia to check drains, trash areas, pet waste, compost, floor drains and any spot where a dead animal could be hidden. The adults you see are only the symptom.
- Time
- 45–90 minutes
- Best for
- Every job; the species points to the breeding site
Light Traps, Baits and Residual Resting-Surface Treatment
$150–$450
For an Olympia restaurant, discreet wall-mounted light traps near the kitchen and prep areas are common. Bright zappers near the front door attract more flies.
- Time
- 1–2 hours
- Best for
- Knocking down adults while sources are fixed
Cluster-Fly Void Treatment, Sealing and Follow-Up Monitoring
$150–$500; follow-ups $50–$150
A good follow-up in Olympia is short and specific. The tech checks activity is down and adjusts placements.
- Time
- 1–3 hours, plus scheduled checks
- Best for
- Cluster flies each fall; ongoing checks for commercial sites
Sanitation, Source Removal and Drain Bio-Cleaning
$100–$350
Often the cure is a hose, brush and bin liner. Larvae cannot develop in clean, dry material.
- Time
- 1–3 hours
- Best for
- House flies, drain flies, fruit flies; the fix that lasts
Prices are typical published ranges. Ask what’s included before you compare quotes.
Cluster flies spend the winter in attics and wall voids, then come out on warm days.Which flies show up around Olympia.
They show up at windows on warm days. Fungus gnats hover around overwatered houseplants. House flies are the most common around Olympia. They breed in trash, compost and manure. Drain flies are tiny and fuzzy. They breed in the slime inside drains. Blow flies are shiny green or blue. A sudden swarm often means something died nearby. Cluster flies hide in attics and walls around Olympia for winter.
Local flies conditions in Olympia.
Knowing Olympia'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 Olympia and Washington 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. Olympia sits in a marine west coast climate, and that sets the pace for fly activity here: spring through fall; cluster flies overwinter indoors. In Olympia, the area is mostly suburban, so flies 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 Olympia usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first.
Trash bins are the top source in summer. Keep lids closed and rinse bins every week or two.Fly season in Olympia.
Seal gaps before September. The season is short but busy. Cluster flies move into walls in fall.
Finding the source.
Likely a dead animal. From Olympia out to Tacoma and Federal Way, trash bins in summer are the usual culprit. Watch where flies gather and where they're coming from. Check trash bins, recycling and compost first. Tape over a drain overnight. Flies stuck to it mean the drain is the source. Bad smell plus big shiny flies?
A year of flies in Olympia.
- Summer: peak season in Olympia. Empty trash often. - Fall: cluster flies move into walls. Seal gaps early. - Winter: cluster flies appear at windows on warm days. - Spring: flies return in May.
Which fly is it?
- Drain fly: tiny, fuzzy, moth-like wings. - Blow fly: shiny green, blue or bronze. - Cluster fly: big, slow, golden hairs. - Fungus gnat: tiny and black, near plants. - Fruit fly: tan with red eyes, near ripe fruit. - House fly: gray, a quarter inch, everywhere.
Cleaning a drain fly drain.
- Enzyme: pour in an enzyme drain cleaner at night. - Repeat: do it daily for a week. - Check: tape over the drain to see if flies still emerge. - Skip: bleach alone doesn’t clear the slime. - Scrub: run a stiff brush down the drain.
Keeping flies out.
- Sweeps: add door sweeps to exterior doors. - Trash: keep lids closed and rinse bins. - Compost: cover it and keep it away from doors. - Pets: pick up waste daily. - Screens: patch holes in windows and doors.
Fly traps that actually help.
- UV light traps: best for kitchens and businesses. - Bait traps: hang them outside, away from doors. - Swatter: still works for a few strays. - Skip: bug bombs. They don’t reach the source. - Sticky ribbons: fine for garages and sheds.
If something died nearby.
A wall may need a small hole opened. The flies stop once the source is gone. Follow the smell and the flies. Wear gloves, bag it, and disinfect the spot.
Flies and pets.
Pet food and waste draw flies fast. Pick up food bowls after meals. Clean up the yard daily in summer. Flies biting a dog's ears are usually stable flies. Ask your vet about protection.
Flies at a business.
Use air curtains or strip doors at busy entries. Schedule drain cleaning and regular service visits. Restaurants and food businesses need a steady routine. Seal dumpsters and clean them weekly.
Flies and food safety.
Throw out food flies have landed on for long. Keep fruit in the fridge in summer. Flies land on trash and then on food. Cover food outdoors and wipe counters often.
What a fly visit looks like.
Then they clean, seal or treat what they find. Traps help confirm the problem is gone. The tech looks for the source first. They check trash areas, drains, attics and gaps by doors.
Screens and doors.
- Doors: add sweeps and keep them closed. - Patio doors: a screen door helps in summer. - Fans: a fan by the door keeps flies moving on. - Screens: patch holes and check the corners.
Compost and yard waste.
Bag clippings. Pick up fruit and pet waste every few days. Flies breed in wet, rotting material. Keep compost covered and turn it often.
Trash day habits.
Keep lids shut and park bins away from doors. Bag food scraps tightly before they go in the bin. Rinse bins every couple of weeks in warm weather.
Questions to ask before you sign.
- Where are they breeding? - What will you clean, seal or treat? - Are follow-up visits included? - Is dead animal removal extra? - What kind of fly is it?
What affects the price
- Number and type of light traps installed.
- Plumbing repairs for slow drains or broken lines.
- Air curtain installation for commercial doors.
- Follow-up visits and monitor replacement.
- Size of the building and attic for cluster flies.
- Number of breeding sources found.
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What bothers you most about flies?
When to call for help
if cluster flies come back every fall. Businesses usually need regular service. Call if you can't find the source after a few days. if you smell something dead in a wall.
What you can do yourself
A pro helps with hidden sources, walls and attics. Clean drains, rinse bins and fix screens. Find the source and remove it. Most home fly problems are DIY.
Flies in Olympia
Olympia has a marine west coast climate, and flies activity here tends to pick up spring through fall; cluster flies overwinter indoors. In Olympia, most of the housing is suburban, so the usual entry points, moisture spots, and sheltered areas near the structure are what an inspection checks first. In Olympia, take a minute to note where you have seen activity and when it appears, so the inspection is faster and the quote more accurate. A local provider who knows Olympia and Washington can point out the specific conditions that matter most here before you commit to a plan. Summer highs near 78°F in Olympia speed up the fly life cycle, so trash and compost need extra care. With about 51 inches of rain a year, damp spots around Olympia also breed small flies. In Olympia's neighborhoods, the usual sources are trash bins, compost, pet waste and drains.
Fly tips from the experts
Where are the flies coming from?
The kind of fly tells you where to look. Around Olympia, Washington, note its size, where it gathers and when it shows up. Then go after the source.
Small flies near drains
Tiny, fuzzy flies near a sink or shower usually breed in the slimy film inside the drain. Scrub the drain with a stiff brush. Spraying the adults won’t stop them.
UC IPM: drain fliesHouse flies around doors and trash
House flies breed in garbage, pet waste and rotting plants. Clear those out first, then add screens and keep doors closed. Traps help, but they don’t fix the source.
EPA: managing fliesWarm weather speeds things up
In warm weather, flies go from egg to adult faster. Take trash out often, rinse bins, and keep screens in good repair. Sprays are a last resort, not a fix.
UC IPM: nuisance fliesBased on guidance from university extension services and the EPA.
How we check our sourcesLocal research
Flies in Olympia, WA: what the public record shows
Before you compare quotes, it helps to know which flies actually live in Washington, when they are busiest around Olympia, and what the state figures look like. Everything below links to the agency or university page it came from.
Fly species recorded in Washington
- House fly (Musca domestica) — Non-biting; breeds in manure, garbage, lawn clippings, decaying produce. 45 days at 60°F to 7 days at 95°F. Carries bacteria and viruses causing diarrhea, cholera, food poisonin…
- Little house fly (Fannia canicularis) — Most numerous in cooler spring and fall; males swarm 5–6 ft above ground in protected areas; develops in animal waste and fermenting grass clippings.
- Flesh fly (Sarcophagidae) — Large gray flies with black stripes; carcasses in attics, chimneys, walls.
When flies are busiest around Olympia
Cool, wet season west of the Cascades slows house fly generations; cluster flies enter buildings in late summer and fall, and drain and phorid flies run year-round indoors.
PNW 770: inspect drains with a flexible borescope or smoke-test plumbing lines, and repair breaks under concrete slabs and remove infested soil where phorid flies are emerging.
Sources: Pacific Northwest Extension (Oregon State University, Washington State University, University of Idaho); Indoor Flies and Their Control; University of New Hampshire Extension; Flies (Home and Landscape). Figures are quoted as the source prints them. How we check our sources
Simple ways to keep flies away
- Keep trash bins closed and rinse them.
- Take trash out often in summer.
- Repair window and door screens.
- Add door sweeps.
- Pick up pet waste daily.
- Clean drains with a brush and enzyme cleaner.
A good quote names the fly, the source, and what will be cleaned, sealed or treated.Did you know?
House flies taste food with their feet
Blow flies can find a carcass within hours
Questions people ask
Will fly spray from the store solve the problem?
It kills the flies you hit. It doesn't remove the source they breed in.
How long does professional fly control take to work?
Usually days, once the source is removed. Cluster flies take a season of sealing.
Can flies come from my neighbor's property?
House flies travel a mile or more. Your own trash and compost still matter most. Yes.
What kind of fly do I have?
Small and fuzzy near drains: drain flies. Shiny green or blue: blow flies. Big and slow at windows: cluster flies.
How do professionals get rid of flies?
They find the source first. Then cleaning, sealing, traps and, if needed, a targeted treatment.
How much does a fly exterminator cost?
Expect a local quote to land above or below it. It's a published estimate, not a local quote. Local quotes vary; ask for a written estimate.
Why does fly extermination cost more for a severe infestation?
Four hundred to 600 dollars is what Local quotes vary; ask for a written estimate.
Are cluster flies common in Olympia?
Yes, they're a fall and winter nuisance around Olympia. Seal gaps around windows and siding before September.
When is fly season in Olympia?
Flies are busiest from about May through September. Cluster flies also appear at windows in winter.
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Sources (13)
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 Fly Exterminator · Updated September 11, 2026 · How we write these guides