Finding blow flies in the house all of a sudden is unsettling. For homeowners, it often sparks worry about hidden decay, bad smells, or germs spreading near family and food.
Blow flies appear when there’s a breeding source close by, usually rotting meat, dead animals, or other decaying organic matter. They’re annoying and a clear signal of a hygiene issue that needs attention.
At Allstate Pest Control, South Australia’s most trusted pest experts for over 35 years, we’ve seen small problems turn into full blow fly infestations in a matter of days, which is why fast action is so necessary.
Why Do I Have Blow Flies in My House All of a Sudden?
Blow flies don’t wander inside for fun. They’re looking for food sources or breeding grounds. Here’s what triggers them:
• Seasonal factors: Warm weather speeds up fly breeding. In summer, blow flies complete a life cycle in as little as 7–10 days. That means one pair can multiply into hundreds within weeks.
• Food sources: Flies love decaying organic matter. Things like rotting meat, animal waste, or open garbage cans with no tight-fitting lids become instant targets.
• Infestation sources: A dead rodent in the roof void. A bird nest in your eaves. Even an unnoticed pet accident indoors. These hidden breeding areas are the most common found in homes.
• Other contributing factors: Open doors, broken flyscreens, or bins left unwashed. All create easy access for bottle flies and adult blow flies to swarm in.
What is a blowfly?
A type of flying insect, blowflies have a characteristic shiny metallic appearance, distinctive large eyes, a set of wings, and grow between 9-22 mm long.
How can I tell the difference between a house fly and blowfly?
Blowflies are larger than house flies, come in different colours and have a metallic sheen.
Reasons to avoid a blowfly infestation
They make distracting buzzing noises, spread diseases, contaminate clean food and surfaces, and outbreaks in businesses can breach health and safety regulations.
Signs you have a blowfly problem
You notice many of them swarming around a particular area, you can hear loud buzzing, or spot their larvae.
How to prevent a blowfly outbreak
We recommend installing flyscreens, keeping waste secured, removing food and water sources and practicing good hygiene around your home.
Professional blowfly management
We use a combination of insecticide aerosol sprays, fogging, dusting, baits, traps and installing fly control units.
Routine pest management for food-handling businesses
To ensure that your business stays compliant with government standards, our 24/7 personalised online portal makes pest management a breeze.
For reliable and fast blowfly treatment, choose Allstate
Our technicians are available 24/7 to all suburbs of Adelaide for innovative solutions to all blowfly problems.
Signs of Blow Fly Infestation in Your House
How do you know it’s more than a few stray flies? Look out for these clear signs:
• Visible flies: Metallic blue or metallic green blow flies hanging around windows. They’re slightly larger than the standard house fly.
• Unpleasant odour: A smell of rotting meat or animal carcasses means a hidden breeding source nearby.
• Larvae and maggots: Spotting maggots in bins, carpet edges, or near drains means larval stages are already active.
• Fly accumulation: Large clusters of adult flies near sunlight or garbage dumps usually mean a blow fly infestation has taken hold.
How to Get Rid of Blow Flies in the House: Step-by-Step Guide
Here’s what you can do before calling the experts.
1. Identify the source: Check bins, pantries, ceiling cavities, or wall gaps for rotting materials or a dead animal. Removing the breeding source is key.
2. Clean and dispose: Seal waste in bags, wash bins thoroughly, and scrub away any organic matter. Rotting meat or dead animals must be removed quickly to reduce infestation.
3. Seal entry points: Repair flyscreens, close windows properly, and keep garbage cans shut with tight-fitting lids.
4. Use natural repellents: Cloves, eucalyptus oil, and vinegar sprays deter flies. These help, but won’t kill off breeding grounds.
Apply fly traps or baits: Store-bought traps catch adult flies, but killing adult flies alone won’t solve the problem if maggots remain.
5. Maintain cleanliness: Regularly wash bins, keep food covered, and clean drains. A clean home cuts down breeding areas.
Keep blowflies at bay this summer. Speak to our expert team.
orEffective Pest Control of Blow Fly Infestations
Successful control depends on whether you are targeting adult flies, larvae (maggots), or both, and on the environment where the infestation occurs.
Here’s a science-based breakdown of the main chemical tools available, plus when and where they’re most effective.
1. Insecticides for Adult Blow Flies
In domestic and agricultural situations in South Australia, synthetic pyrethroids remain the primary choice.
• Permethrin: Common in household fly sprays, residual surface sprays.
• Cypermethrin: Residual sprays and perimeter treatments.
• Deltamethrin: Available for household and farm use.
• Bifenthrin: Used in some residual surface sprays outdoors.
Note: Organophosphates such as Diazinon and Chlorpyrifos, and carbamates such as Propoxur, are not permitted for household use in South Australia. Diazinon is still in some sheep drench/dip products but is being phased out.
2. Larvicides for Blow Fly Maggots
Most effective and widely used in livestock blowfly strike prevention.
• Cyromazine: Leading product for sheep blowfly strike prevention (e.g., Clik, Vetrazin).
• Diflubenzuron: Used for livestock blowfly protection in some formulations.
• Dicyclanil: Widely used in sheep for long-lasting blowfly strike protection.
• Methoprene: Permitted in some manure and waste treatments as a larvicide and growth regulator.
3. Baits and Traps for Adult Flies
Registered blowfly and housefly baits in Australia rely mainly on neonicotinoids or methomyl.
• Imidacloprid: Found in granular fly baits such as QuickBayt.
• Thiamethoxam: Used in some bait formulations.
• Methomyl-based baits: Effective but more restricted, available mostly to agricultural users.
Get on top of a blowfly outbreak quickly. Speak to an expert today.
or4. Disinfectants and Sanitation Aids
These are unrestricted and vital for blow fly control.
• Phenolic disinfectants: Used in livestock sheds and waste facilities.
• Quaternary ammonium compounds: Common in sanitising solutions.
• Lime (calcium hydroxide): Neutralises organic waste and suppresses maggot breeding sites.
When to Call in the Experts
DIY can help reduce numbers. But sometimes it’s not enough.
Persistent swarms mean there’s a hidden breeding source, like a dead rodent on the roof. Health concerns also come into play. Flies can transfer bacteria from decaying organic matter to food, increasing risk of diarrhoeal disease. That’s when expert fly control is the safest option.
Why Allstate Pest Control is the Right Choice for Blow Fly Infestation
At Allstate Pest Control, we handle fly infestations daily across Adelaide. Here’s why locals rely on us:
• Expert knowledge: Our technicians know the behaviour of blow flies, bottle flies, and the most common flies found in South Australian homes.
• Tailored solutions: Every property is different. We locate the breeding source, whether it’s garbage dumps, animal carcasses, or hidden rotting materials.
• Fast and efficient service: With 24/7 emergency response, we act quickly to protect your home or business.
• Health & safety: Our blow fly control methods are designed to prioritise family and pet safety while reducing breeding grounds in the long term.
If you’re a business, especially in food handling or meat processing plants, commercial fly control is essential. Call the experts on 08 8371 1277 before they become a nuisance to customers and staff.
Frequently Asked Questions
How long does it take to manage blow flies in the house?
It depends on the breeding source. Once the source is removed, adult flies can die out within days. Severe infestations may need professional treatment to break the life cycle.
Are blow flies dangerous to humans?
Yes. Blow flies can bite humans in rare cases, but the bigger risk is disease. Blow flies carry bacteria from animal waste, rotting meat, and open wounds, spreading it onto food and surfaces. They carry pathogens that cause illnesses like dysentery, typhoid, and cholera, as well as other diseases like salmonellosis and potentially, gastritis, ulcers, and stomach cancer.
How do I prevent blow flies from coming back?
Keep bins sealed, clean drains, and cover food sources. Check regularly for dead animals in the roof or wall cavities. Prevention is about removing every breeding source that flies love.
Blow Flies Point to Bigger Problems. Address It Now!
Blow flies in the house are more than a nuisance. They point to a deeper hygiene issue, whether it’s rotting meat in the bin, a dead rodent in the ceiling, or another hidden breeding source. Acting fast keeps your family safe, and if things don’t settle, calling in experts is the smartest move.
For fast, reliable blow fly control anywhere in Adelaide, call Allstate Pest Control on (08) 8371 1277 or reach out to us online.
Our expert team is ready to help you now.
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