How to Get Rid of House Flies (Both Inside and Outside Your Home)

Flies are buzzing, annoying pests, and they’re the last visitors you want flying around your kitchen or swarming your outdoor space.

Fortunately, you don’t have to live with flies forever.

Here at The Pest Dude, we help customers in and around the San Francisco Bay Area learn how to DIY their pest control with tips and tricks we’ve field-tested ourselves.

In this blog, we’ll share our top tips on getting rid of flies on your own and preventing future fly problems.

What are Flies?

Flies are pests that have lived near humans for thousands of years. While some flies suck blood, others are scavengers that consume waste and food scraps.

Flies carry and spread more than 100 different disease organisms and are strongly associated with disease transmission.

Specifically, filth flies spread diseases like typhoid, paratyphoid, cholera, dysentery, pinworm, roundworm, whipworm, hookworm, and tapeworm.

Although flies reproduce fastest during the summer, they breed all year around and can become an issue regardless of the season. Adult flies only live 10-25 days, but females lay hundreds of eggs in that time, so infestations can quickly spiral out of control.

Although experts estimate that there are over 110,000 species of flies worldwide, filth (domestic) flies are the species that are most likely to affect humans.

Filth flies, including bottle flies (also known as blow flies), are members of the order Diptera, and are sometimes known as “true flies.” These flies have two wings rather than the four wings found on most other winged insects.

Filth flies can be categorized into two groups according to their appearance and food preferences: large and small filth flies.

• Large filth flies, such as house flies and cluster flies, have stout bodies and short legs. They feed on manure, garbage, and carrion.
• Small filth flies, like fruit flies, have slender bodies and long legs. They commonly feed on drain sludge and rotting plant material.

Filth flies have evolved to live close to humans and are usually found in or near homes and other structures.

While filth flies are annoying, they can also be a public health risk. As their name implies, filth flies live in unsanitary conditions, often feasting on trash, sewage, and rotting meat.

As they feed, these flies pick up pathogenic organisms on their mouthparts, which they then transmit to human and animal food.

Why Are Flies Attracted To My House?

Wondering why you have flies in or around your home? Here are a few things that could be attracting them:

1. Food sources

Filth flies feed and lay their eggs on moist organic material. They’ll also feed on sweet or fermented liquid from rotting fruits, veggies, food spills, or beer.

2. Other flies

When flies feed, they leave “fly specks.” These tiny brown or black dots are a mixture of excrement and excess saliva.

Fly specks can appear on or near food sources and will attract other flies, who use existing fly specks to find food sources.

3. Moisture

Flies are highly moisture-dependent.

In fact, they need moisture for everything they do: they can only lay their eggs on moist surfaces, and they can only consume the liquid of soluble foods.

As such, homes and outdoor spaces with lots of moist areas are more likely to attract flies.

How to Get Rid of Flies in the Home

If flies have invaded your home, there are specific steps you need to take, including:

1. Focus on sanitation

Good sanitation is the first step in all fly management. Start by removing food and other materials that flies may eat or lay their eggs on.

Here are a few tips:

• Store produce in the refrigerator rather than on the counter
• Remove pet food and water bowls
• Clean and sanitize food preparation areas like cutting boards, stovetops, and sinks
• Keep all garbage secured in bins with tight-fitting lids and cover countertop compost bins.

2. Use fly traps

Fly traps or flypaper are effective ways to manage flies indoors. These traps can be purchased at home goods or hardware stores and usually feature a sticky surface covered in a material that’s attractive to flies.

While fly traps will kill adult flies, they can be unsightly indoors and are most effective when used in conjunction with other fly management techniques.

Alternatively, you can use electrically charged screens or insect light traps (like this one). These traps use blue light or UV rays to attract flies and then kill them with a hidden sticky surface or an electrical charge.

Unlike fly strips, these traps are low-profile, and most contain dead flies in sleek, no-touch containers, which makes them well-suited for indoor use.

You can also use an electric fly swatter to kill adult flies as they appear in living spaces or buildings. Here’s one we recommend.

3. Use contact sprays

Contact sprays approved for indoor use provide quick knockdown for adult flies but no residual protection.

These formulas can be applied with fogger or aerosol equipment but should not be used in food preparation areas. For the easiest application, we recommend an aerosol formula like PT 565 Plus.

Note: Contact sprays contain harsh chemicals and should only be used when infestations are severe. Otherwise, we recommend using non-chemical methods, like electric fly swatters, instead. 

4. Consider residual insecticides

Flies commonly hibernate in the walls of buildings during cold weather and emerge when the temperatures begin to rise, leading to frustrating, full-blown indoor infestations.

To kill hibernating flies in wall voids, use a long-lasting residual insecticide. We recommend using a dust formulation like this one since dusts are easy to apply into small wall voids with handheld dusters or small power dusters.

How to Get Rid of Flies Outside

If you’re dealing with flies in your yard or garden area, take the following steps to address the infestation.

1. Remove food sources

To get rid of flies in your outdoor spaces, remove materials they’re feeding and laying eggs on, just like you would indoors.

We recommend keeping outdoor garbage secured in solid cans with tight-fitting lids and removing it at least twice a week.

Outdoor compost bins or piles should be located far from the house, and food spills from outdoor barbecues or picnics should be cleaned up promptly.

Since flies also love to lay eggs in excrement, promptly pick up all pet waste and dispose of it in sealed plastic bags in a closed trash can.

2. Set fly traps

Fly traps can be as effective outdoors as they are indoors. For outdoor use, we recommend disposable traps like these, which use an attractant bait to draw flies in.

These traps are excellent for containing and killing adult flies and can help you get even severe infestations under control quickly.

3. Use residual insecticides

Because fly traps won’t eliminate a fly infestation alone, we recommend leveraging residual insecticides approved for outdoor use, like this one.

The most effective formulations are “adulticides,” which include pyrethroids, boric acid, and other insecticides labeled for outdoor fly management of adult flies.

To get the most bang for your buck, we recommend looking for wettable powder, soluble concentrate, or microencapsulated formulas that stick to the insects’ bodies and provide the best residual control.

These formulas should be applied to outdoor surfaces where flies rest, including porches, garbage cans, vegetation, and more.

Be sure to follow all label directions closely and take appropriate safety precautions whenever you apply insecticides.

4. Set insecticide baits

Insecticide baits are approved for outdoor use and can kill flies rapidly.

Despite their initial efficacy, however, their effects are short-term – unless you combine them with other treatments, like traps and residual insecticides.

We recommend using baits as a complement to a residual insecticide spray program, and choosing wet bait formulations, like this one, that you can spray or sprinkle onto fly resting surface outside the home.

Dry baits (like this formula) can also be scattered around garbage cans to kill adult flies and bring infestations under control.

How do Exterminators Get Rid of Flies?

Here’s the process most professional pest control experts follow:

1. Inspection

Pest management teams always begin with an inspection, during which they identify the species of pest present, assess current levels of pest damage, and develop a customized treatment plan.

2. Treatment

Next, the pest management team will deliver their chosen control method.

To get rid of pests like flies, most teams use a combination of approaches, including sanitation, exclusion, trapping, and residual pesticide application.

3. Follow-up treatment

After the initial treatment, the pest management team will revisit your property to provide follow-up treatments, as needed.

Because flies multiply rapidly, it may take more than one treatment application to kill all adults, eggs, and larvae and control the infestation.

How to Prevent Fly Infestations

Keep flies from coming back with these tips:

• Use mesh screens on windows and doors. To prevent flies from accessing your home, the mesh should be no larger than 12 to the inch for larger flies and 18 to the inch for smaller filth flies. To prevent flies from entering your home easily, make sure all screen doors open outward.
• Seal exterior cracks. To keep flies out of living and working spaces, use caulk or foam sprays to seal all cracks around window and door frames, electrical outlets, heating and AC vents, light fixtures, and other possible access points.
• Use natural repellents. Essential oils, including neem and peppermint oil, have been shown to repel adult flies. For best results, create a homemade repellent spray by mixing the essential oil with water in a spray bottle and spraying the mixture on outdoor furniture, picnic tables, and other areas you want to protect from flies.
• Keep your grass and landscaping trimmed. To prevent fly infestation outdoors, trim your grass, landscaping, and ornamental plants. This reduces fly resting areas and forces flies to land on hard surfaces, like outdoor furniture, where residual insecticides can be used most effectively.
• Limit moisture. Remove moisture sources in your home by cleaning up spills promptly, fixing leaking or dripping sinks, faucets, or drains, and watering indoor plants once a week or less. Use vent fans in high-moisture areas, like bathrooms and kitchens, and fix any slow-draining sinks or bathtubs. Keep moisture levels as low as possible outdoors by removing sources of standing water and removing damp, decaying organic matter like leaves, rotten wood, and more.
• Remove food sources. Keep flies away by removing their food sources. Wipe down all surfaces after cooking or preparing food, and clean up spills and leftovers promptly. Avoid leaving dirty dishes outside or in the sink, and store pet food in secure, insect-proof containers.

Are You Tired of Sharing Space With Flies? We Can Help!

Flies are annoying, disgusting, troublesome pests that can take over your home and yard at any time of the year.

Fortunately, you don’t have to settle for living with flies forever.

If your DIY methods have failed or you need more assistance getting rid of flies, we’re here for you.

We work with an extensive network of reputable, local partners that can help you in your area.

Contact us today at (844) 532-0076 or fill out the form below, and we’ll connect you to one of our local partners.