The short version
Around Allentown, flies are busiest from about April into October. 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 Allentown 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 Allentown 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
Residual products are applied to the spots flies land: ceiling edges, cords, door frames and sunny exterior walls in Allentown. Flies pick up the product while resting.
- Time
- 1–2 hours
- Best for
- Knocking down adults while sources are fixed
Exclusion: Screens, Door Sweeps and Air Curtains
$150–$450 (air curtains more)
Exclusion is the part of fly control in Allentown that keeps working without anyone thinking about it. Screens and sweeps do not need refilling or replacing every month.
- Time
- 1–4 hours
- Best for
- Buildings with steady fly entry from outside
Sanitation, Source Removal and Drain Bio-Cleaning
$100–$350
Once the source is found, an Allentown technician removes or treats it: spoiled material bagged and taken out, pet waste cleared, bins cleaned and drains scrubbed. Without this step, flies return within days.
- 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 Allentown.
Blow flies are shiny green or blue. A sudden swarm often means something died nearby. Cluster flies hide in attics and walls around Allentown for winter. They show up at windows on warm days. Fungus gnats hover around overwatered houseplants. House flies are the most common around Allentown. They breed in trash, compost and manure. Drain flies are tiny and fuzzy. They breed in the slime inside drains.
Local flies conditions in Allentown.
An inspection in Allentown usually starts outside and works inward, checking the foundation, gaps around doors and windows, and any moisture or clutter near the structure first. Knowing Allentown'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 Allentown and Pennsylvania 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. Allentown sits in a humid continental climate, and that sets the pace for fly activity here: spring through fall; cluster flies overwinter indoors. For Allentown homes, the area is mostly urban, 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.
Trash bins are the top source in summer. Keep lids closed and rinse bins every week or two.Fly season in Allentown.
Cluster flies move into walls in fall. Seal gaps before September. Numbers peak in mid to late summer.
Finding the source.
Flies stuck to it mean the drain is the source. Bad smell plus big shiny flies? Likely a dead animal. From Allentown out to Bethlehem and Easton, 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.
A year of flies in Allentown.
- Summer: peak season in Allentown. Empty trash twice a week. - Fall: cluster flies look for a way in. Seal gaps. - Winter: fix screens and doors. - Spring: flies return. Check screens.
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.
Clean up the yard daily in summer. Flies biting a dog's ears are usually stable flies. Ask your vet about protection. Pet food and waste draw flies fast. Pick up food bowls after meals.
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.
Rinse bins every couple of weeks in warm weather. Keep lids shut and park bins away from doors. Bag food scraps tightly before they go in the bin.
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 of drains needing bio-cleaning.
- Number of breeding sources found.
- Opening and repairing a wall or ceiling void.
- Follow-up visits and monitor replacement.
- Size of the building and attic for cluster flies.
- Air curtain installation for commercial doors.
📊
What bothers you most about flies?
When to call for help
Call if you can't find the source after a few days. if you smell something dead in a wall. if cluster flies come back every fall. Businesses usually need regular service.
What you can do yourself
Most home fly problems are DIY. Find the source and remove it. Clean drains, rinse bins and fix screens. A pro helps with hidden sources, walls and attics.
Flies in Allentown
Summer highs near 85°F in Allentown speed up the fly life cycle, so trash and compost need extra care. With about 45 inches of rain a year, damp spots around Allentown also breed small flies. In denser parts of Allentown, dumpsters, alleys and restaurant trash are the big sources.
Fly tips from the experts
Where are the flies coming from?
The kind of fly tells you where to look. Around Allentown, Pennsylvania, 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 fliesSlow flies at the windows in fall?
In colder states like Pennsylvania, sluggish flies at upstairs windows in fall, winter or early spring are often cluster flies. They spend winter in attics and walls but don’t breed indoors. Sealing gaps outside in late summer keeps them out.
University of Minnesota Extension: fliesBased on guidance from university extension services and the EPA.
How we check our sourcesLocal research
Flies in Allentown, PA: what the public record shows
Before you compare quotes, it helps to know which flies actually live in Pennsylvania, when they are busiest around Allentown, and what the state figures look like. Everything below links to the agency or university page it came from.
Cluster fly generations per year in Pennsylvania
Each summer generation adds to the population that moves into attics and wall voids in fall.
Penn State ExtensionCluster fly larval host
No garbage or drain source exists to clean up, so exclusion is the only real fix.
Penn State ExtensionFly species recorded in Pennsylvania
- 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…
- Stable fly (Stomoxys calcitrans) — Biting fly with bayonet-like proboscis; about 12 days egg to adult; peaks early summer.
When flies are busiest around Allentown
Cluster flies enter structures with the onset of autumn after three to four summer generations; filth fly pressure near dairy and hog operations runs late spring through fall.
Penn State Extension: mechanical exclusion is the best method, sealing cracks around windows, doors, siding, utility pipes, and behind chimneys; insecticide treatment of the dead flies invites carpet beetles.
Sources: Penn State Extension; USDA National Agricultural Statistics Service; Texas A&M AgriLife Extension; 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?
Blow flies can find a carcass within hours
Phorid flies prefer running to flying
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 do restaurants control flies?
Strict cleaning, sealed trash, air curtains and fly lights. Drains get cleaned on a schedule.
Are fly control treatments safe for kids and pets?
Used by the label, yes. Traps and sealing are the gentlest options. Ask what product they use.
What are cluster flies and why are they in my attic?
They're large, slow flies that winter in walls and attics. They come out on warm days and gather at windows.
What kind of fly do I have?
Big and slow at windows: cluster flies. Small and fuzzy near drains: drain flies. Shiny green or blue: blow flies.
Why do tiny flies run across my counter?
For Allentown homes, in the 2012 study by Bertone and colleagues, phorid flies were found in 82% of the 50 North Carolina homes inspected, making them one of the most widespread flies indoors. Treat it as a rough guide, not a local count.
Why do I suddenly have big shiny flies in my house?
For Allentown homes, a sudden cluster of shiny blue or green flies often signals a dead animal in a wall or attic: Bertone and colleagues found blow flies in 48% of 50 North Carolina homes in 2012.
Are cluster flies common in Allentown?
Yes, they're a fall and winter nuisance around Allentown. Seal gaps around windows and siding before September.
When is fly season in Allentown?
Flies are busiest from about April into October. Cluster flies also appear at windows in winter.
Nearby cities
Related guides
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