Do Flies Go Away in the Fall? What Businesses Need to Know
As a business owner, you might hope fly problems slow down after summer — but for many facilities, that’s not the case. Small flies like fruit flies, phorid flies and drain flies can stay active year-round, continuing to create challenges for your staff and customers. These issues don’t just cause annoyance — they can impact customer experience, sanitation standards, inspections and ultimately your business reputation.
While outdoor fly activity may slow as temperatures drop, indoor spaces still offer warmth, moisture and food — the perfect conditions for flies to stay active. With the right prevention steps, you can help ensure your facility stays protected year-round.
Where Do Flies Go in the Fall?
1. Outdoor Flies: Most flies that thrive outdoors will seek shelter to survive the cold. Many species enter a state like hibernation, called diapause. They’ll hide in protected places like decaying organic matter, loose soil or under piles of leaves and bark. These spots provide insulation from the freezing temperatures, allowing them to survive until spring.
2. Indoor Flies: Flies like cluster, small flies and face flies search for warmth indoors as temperatures drop. They enter through open doors, vents, damaged screens or foundation cracks, then rest in quiet areas such as wall voids, attics or basements. Other common flies — like houseflies — may stay active year-round by breeding in warm, moist areas such as kitchens, garbage cans and drains.
Why Do Businesses Still See Fly Problems in the Fall?
1. Temperature-Controlled Environments: Facilities like restaurants, grocery stores and food processing plants maintain consistent indoor temperatures year-round. These warm, climate-controlled spaces create an ideal environment for flies to remain active, feed and reproduce.
2. Food and Waste Management Issues: Organic waste and food debris provide reliable food sources, no matter the season. Dumpsters, drains and improperly managed trash can become breeding grounds if not cleaned and maintained regularly.
3. Doors and Loading Docks: High-traffic areas with frequently opening doors, especially in warehouses and loading docks, allow easy access for flies seeking warmth and shelter.
4. Moisture and Sanitation Zones: Drains, beverage stations and other damp areas attract small flies — like drain or phorid flies — that continue breeding indoors even in colder weather.
5. Seasonal Changes: As autumn temperatures fall, some flies are drawn to the warmth radiating from buildings. The sunny side of a structure or unsealed entry points can attract and allow flies inside to overwinter.
What Industries Are Most at Risk for Flies During the Fall?
1. Restaurants and Food Processing Facilities
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Food waste and scraps provide an abundant food source for flies.
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Warm kitchens and storage areas offer ideal breeding conditions.
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Frequent opening and closing of doors allow flies easy access.
2. Warehouses and Distribution Centers
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Large doors and open spaces make it difficult to prevent fly entry.
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Stored perishables or packaging waste attract flies.
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Cracks, crevices and high ceilings offer ample hiding spots for flies to breed.
3. Hotels and Hospitality Businesses
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Dining areas and foodservice attract flies with spills and food waste.
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High foot traffic increases the chances of flies entering the building.
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Decorative water features or outdoor landscaping can serve as breeding grounds.
4. Healthcare and Senior Care Facilities
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Foodservice areas and leftover food attract flies.
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Trash areas and biohazard waste provide breeding sites.
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The need for fresh air and ventilation can make it harder to seal off entry points.
Understanding Fly Behavior as Temperatures Drop
As temperatures cool, fly activity doesn’t stop — it just changes. Knowing how temperature affects their movement and reproduction helps businesses adjust prevention plans and stay ahead of potential infestations.
How Cooler Temperatures Slow Fly Activity and Movement
Flies, like all insects, are ectothermic or "cold-blooded." This means they cannot generate their own body heat and rely entirely on the external environment to regulate their internal temperature. Their body temperature, plus their ability to function, mirrors the temperature of their surroundings.
When the weather is warm, a fly's internal systems operate at peak efficiency. Their muscles can contract quickly, their metabolism runs high, and all their biological processes are optimized for speed and activity. This is why summer is the season of the fly.
As temperatures begin to fall, everything slows down. The chemical reactions that power their bodies happen more slowly, leading to a noticeable decrease in energy and movement. A fly that could zip around a room with lightning speed in August becomes a lumbering, easily swatted nuisance in October.
How Cooler Temperatures Slow Fly Reproduction
Temperature doesn't just slow flies down; it brings their reproductive cycle to a grinding halt. Flies are known for their incredibly fast life cycle, but this is only possible under ideal, warm conditions.
A female housefly can lay hundreds of eggs in her short life. In peak summer heat (around 85°F or 30°C), the entire cycle from egg to adult can take as little as seven to ten days. This explosive reproductive rate is what leads to large fly populations during the summer.
Common Flies You May Still See
Not all flies are the same, and knowing what you’re up against helps you act faster. A few common culprits that often persist into the fall include:
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Houseflies: General nuisance pests that feed on a wide range of organic materials.
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Fruit Flies: Small but persistent, drawn to overripe or fermenting produce and sugary residues.
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Drain Flies: Breed in untreated drains and organic buildup.
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Cluster Flies: Often invade buildings for shelter, sometimes appearing in higher numbers as the weather cools.
Each fly species poses different challenges, but they all risk contaminating food and damaging your reputation.
Why Fall Fly Control Matters for Businesses
Even a few flies in sight can put customer trust at risk, especially in food‑ and service‑focused industries. Beyond negatively influencing customers’ perception of your business, flies can:
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Spread bacteria and pathogens
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Trigger health and safety concerns
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Lead to citations during inspections
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Impact productivity if infestations spread inside and lead to interrupted operations
In short: Flies don’t tend to take the fall off, and neither should your pest management strategy.
Fall Fly Prevention Tips for Businesses
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Inspect and Seal Entry Points: Windows, vents and doors.
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Maintain Sanitation: Remove trash frequently and clean drains.
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Monitor Moisture: Fix leaks and manage humidity levels.
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Use Professional Fly Management Solutions: Traps, monitoring and treatments.
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Partner With Pest Control Experts: Implement seasonal fly management programs.
How Orkin Can Help Protect Your Business Year‑Round
Relying on a seasonal approach to fly control isn’t enough. Orkin Pros are trained to identify which flies you’re dealing with, target their breeding areas and develop control plans tailored to your facility. Our program focuses on:
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Sanitation Support: Providing guidance on cleaning schedules and waste management.
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Exclusion Strategies: Helping to reduce entry points around your building.
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Targeted Treatments: Offering solutions to disrupt fly breeding cycles indoors and outdoors.
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Ongoing Monitoring: Including regular inspections that adapt with seasonal shifts.
Why You Need to Be Prepared for Flies
Flies don’t simply disappear when the leaves change. For facilities with dumpsters and drains, fall can still bring plenty of fly activity. Staying proactive now means fewer problems later — and less risk to your reputation.
Don’t let flies catch your business off guard this fall. Schedule a free inspection with an Orkin Pro™ today and gain absolute confidence that we’ll help your facility is protected year-round.
Have more questions about fly control for your business? Discover more answers from Orkin’s experts.
Fly Pest Control FAQs
How do I get rid of flies in my business?
Thorough sanitation, removing waste promptly, keeping garbage covered and sealing entry points are essential. Regular professional inspections and targeted treatments from a pest control provider like Orkin can help keep flies from returning.
Why does my office have so many flies?
Flies are attracted to food debris, waste, moisture and poor sanitation. Common sources include overflowing trash bins, uncovered foods, dirty drains or structural gaps letting flies inside.
How do I find the source of flies?
Track down areas with food debris, dirty drains, waste buildup or standing water. Flies seek out organic matter to breed and feed — any of these can be a source. A professional inspection can uncover hidden hot spots.
What types of flies are most problematic in commercial settings?
Houseflies, fruit flies and drain flies are common. Each can contaminate food and surfaces — carrying bacteria and threatening your facility’s reputation.
What are early signs of a fly infestation?
More frequent fly sightings, flies gathered near waste, food prep or drains, and increased captures in fly traps indicate a growing problem. Maggots in waste areas are another clear warning sign.
How can I keep flies outside of my business?
Exclusion techniques can support fly prevention at your facility: seal gaps, install vinyl strip doors and weather stripping, consider air curtains, and maintain positive building pressure to limit fly entry.
Are flies a food safety risk?
Yes. Some flies can transfer bacteria to food and surfaces, increasing risks of contamination, inspection findings and brand damage in food handling facilities.
How do I know if I need professional fly control?
If sightings persist after you’ve implemented a sanitation and exclusion plan, or if traps capture more flies week after week, bring in a provider to identify the fly species, sources and targeted treatment options.