Yes, pest control professionals can get rid of flies, and they’re particularly effective for infestations that keep coming back despite your own efforts. A typical treatment runs $175 to $300, with the national average around $250. But here’s what most people don’t realize: no amount of insecticide will permanently solve a fly problem if the source attracting or breeding them isn’t eliminated first. That’s actually the main thing a good exterminator will help you identify.
What Pest Control Technicians Actually Do
A professional fly treatment isn’t just someone spraying chemicals around your house. The process starts with an inspection to figure out what type of fly you’re dealing with and where they’re breeding. This matters because house flies, drain flies, blow flies, and cluster flies all require different approaches. House flies breed in animal waste and decaying garbage. Blow flies (the shiny green or blue ones) usually mean a dead animal is decomposing somewhere nearby, often a rodent inside a wall. Drain flies are reproducing in the organic sludge lining your pipes. Cluster flies hide inside walls and attic spaces during cooler months.
Once the source is identified, technicians use a combination of tools. For active infestations indoors, they apply fast-acting sprays that knock down and kill adult flies on contact but don’t provide long-lasting protection. For outdoor areas like porches, garages, patios, and around garbage cans, they apply residual sprays (typically permethrin-based) that continue killing flies for weeks after application. They may also set up insect light traps in problem areas, apply bait formulations near fly resting spots, or use dust insecticides in cracks and crevices where flies enter or hide.
For drain flies specifically, the treatment is different. Technicians coat the inside of affected drains with a bio-gel that breaks down the organic buildup where larvae develop. This treatment is repeated nightly for one to two weeks. Glue boards placed near drains and residual aerosols sprayed around sinks help catch adults while the gel eliminates the breeding site.
Why Flies Come Back After Treatment
The house fly lifecycle explains why a single treatment rarely solves the problem permanently. A female fly can lay eggs within days of emerging as an adult. Those eggs hatch in as little as 8 to 20 hours, and larvae can develop through all their stages in 3 to 7 days under warm conditions. The pupal stage adds another 3 days to 4 weeks depending on temperature. This means a new generation of flies can appear every one to two weeks during warm months, with six to eight generations produced per year.
Contact sprays kill adult flies but don’t touch eggs or pupae already developing in breeding material. That’s why pest control companies often recommend follow-up visits, and why the real fix is eliminating whatever the flies are breeding in. If your technician treats the house but a pile of dog waste sits in the yard, new flies will hatch and find their way back indoors within days.
What You’ll Need to Do Before Treatment
Professional treatments work better when you prepare the space. Before the technician arrives, remove food, dishes, utensils, and towels from kitchen cabinets and countertops. Pull the refrigerator and other large appliances at least a foot from the wall so the technician can access those areas. Vacuum all carpeted surfaces thoroughly, especially along baseboards and under furniture, and damp mop hard floors along edges and corners.
All people and pets need to leave during treatment. For general pest treatments, plan to stay out for at least two hours. Remove pet food bowls, water dishes, bedding, and toys from treated areas. If you have fish tanks, cover them with a towel and consider turning off central air to prevent circulating airborne residue through the house. When you return, wipe down countertops and cabinet interiors before putting items back, but leave baseboards and crevices untouched so the residual treatment can keep working.
Costs by Treatment Type
The method your exterminator uses affects the price. Bait-only treatments sit at the lower end, around $125. Trap installations cost roughly $145. Chemical treatments using residual sprays average $250, which is the most common approach for a standard house fly infestation. More severe or complex infestations involving multiple treatment types can reach $375. Some companies offer recurring service contracts for properties with ongoing fly pressure, like homes near farms or livestock, which may reduce per-visit costs but add up over the season.
Sanitation and Exclusion: The Permanent Fix
Pest control professionals will tell you the same thing that entomologists at every major university extension program emphasize: insecticides alone cannot rid a property of flies. Sanitation is the first line of defense, and without it, treatments provide only temporary relief.
Start with garbage management. Trash cans need tight-fitting lids, ideally spring-loaded ones that close automatically. All food waste should be drained, sealed in plastic bags, and placed in cans or dumpsters. Empty indoor trash daily and outdoor bins at least once or twice a week. If you have outdoor dumpsters, position them at least 50 feet from doors and windows, and ideally upwind from your home’s main entry points. Rinse all cans, bottles, and plastic containers before recycling or discarding them.
Animal waste is a major breeding ground. If you have pets, pick up waste from the yard at least twice a week. For properties with livestock, manure should be removed weekly and disposed of away from the home.
Exclusion keeps new flies from entering. Make sure all window screens fit tightly with no gaps or tears. Check every exterior door for gaps at the base and install door sweeps where needed. Seal cracks around the building exterior, especially near the roofline and around utility penetrations. Keep exterior doors closed between uses rather than propped open. For kitchens with persistent problems, air curtains installed above doorways blow outward and create an invisible barrier that flies can’t easily cross.
Fix leaking drains and garbage disposals promptly, since any place where food waste and moisture accumulate becomes a potential breeding site. Floor drains in kitchens, laundry rooms, and garages should be cleaned regularly to prevent organic buildup. Trim shrubs and tree branches back at least 6 inches from your roofline and siding to reduce shaded, moist resting spots that flies favor.
Cluster Flies and Face Flies: A Harder Problem
If your fly problem peaks in late summer, fall, or on warm winter days, you’re likely dealing with cluster flies or face flies rather than common house flies. These species overwinter inside wall voids, attics, and other hidden spaces, making them especially difficult to control once they’re established indoors. Technicians treat these by applying residual sprays to attics, basements, closets, and storage rooms where the flies congregate. But because the flies hide deep inside walls and other inaccessible areas, complete elimination in a single treatment is unlikely.
The best strategy for cluster and face flies is prevention before they move indoors. Sealing cracks, gaps around windows, and openings in the building exterior in late summer, before the flies begin seeking shelter, is far more effective than trying to treat them once they’ve settled in for the season.