Every household has had an infestation of flies at one point or another. They seem to come out of nowhere and, like any bad houseguest, don’t want to leave.
Flies are most likely to enter your home during the Summer and Fall months. Most typically, they enter your home because of:
- Light in your home
- Rats and mice
- Fruit past its prime
- Dirty drains
- Growing vegetables Indoors
- Pet food and droppings
- Open windows and ripped screens
Don’t worry! You can take care of many of these issues with relative easy. Below, we’ve broken down some of the biggest issues you might face and what to do about them – let’s get to it!
Flies… Why Are There so many In My House?
There are over 100,000 species of flies, according to the University of Missouri Extension Office. That’s SO many when you think about it and leaves quite the potential for many to get inside your home,
In North America alone, there are over 16,000 types of flies. Many of them are attracted to the same problems or stimuli. Once you resolve or remove these issues, your fly problems may very well go away!
So, let’s dive into just why flies are in your home in the first place and what to do about each specific, common issue:
Bright Lights Attract Flies
Certain types of flies are attracted to light and will move towards it, invariably bringing them into your well-lit home. Cluster flies are a type of fly that will come into your home to follow the light.
Cluster flies are larger than the standard house fly with dark gray coloring and wings that overlap at the end. If you’ve ever seen a fly fall on the ground upside down and spin around, you’ve seen a cluster fly.
Since cluster flies give off a sweet odor, they attract each other into large groups, earning the title cluster flies. If one of these flies is killed, the sweet odor is released in an even stronger concentration, causing all the flies to come together and creating a larger swarm.
You’ll see these flies congregate around your home in fall and winter, as the weather cools off, and they need to look for shelter.
The cluster flies will try to find a way inside and if they can’t find a way inside, they might try hiding in the crevices and nooks along the exterior of your house.
How To Fix It
The female cluster flies lay their eggs in the soil where the larvae dig down, looking for earthworms. When the small find an earthworm, they burrow inside and feed.
Once the temperature rises in the spring, the adults fly and start laying eggs until it gets cold enough to look for ways inside. Homes that have a lot of shade around them have a lower population of earthworms and without that food source, cluster flies will be less likely to lay their eggs around your home.
If you’d like, take a look at our article to find out where flies are most likely to lay their eggs to help deter them!
Specifically, having good shade around your home can help really prevent this type of fly.
Also, camphor trees will repel flies if you live in zones 9-11 and have them planted around your house. The smell is a mild deterrent to the flying invaders.
If you find yourself with a cluster fly problem, take fly prevention steps: caulking up any openings into your home and using window screens. Look for openings around not only windows and doors but also screens and vents.
Fly strips hung up around the swarming flies will reduce their numbers and help get the infestation under control. These sticky strips of paper will catch and hold the flies and as the cluster flies die, they release the sweet odor and draw in other cluster flies in the area.
Try these Fly Paper Strips if you need help lowering the fly population in your home!
Rats And Mice Can Bring Flies In
If you’ve recently had a problem with mice or rats scurrying around your home, you might have thought that was the worst of your infestation problems. After fighting a losing battle with traps, you decide to step up the attack and bring in the rodenticide to help fight the good fight at large.
It’s all well and good, the rodents have stopped invading your pantry and cabinets.
Suddenly you have a fly problem. It seems like a fly infestation goes from zero to “oh no!” overnight.
Specifically, blow flies and flesh flies are the most common types you’ll see gathering around left over animals or insects. Yuck.
These flies are identified by shiny blue to green or yellow color and might be called bottle flies or blow flies. The most annoying part of having these blow flies in your home is the buzzing sound they make.
They can also land on food, bringing over everything else they’ve landed on with them to where they’re now landing in your home.
How To Fix It
Since the gasses from decaying animals attract these flies, when you’ve had something under your floors or in your walls for a while, they come and lay hundreds of eggs.
Their sense of smell and strong flying allows them to find a leftover animal in minutes.
Once a fly lays eggs on their target, the larvae will hatch and feed. These are called maggots.
While these maggots are wonderful in nature to help speed the decomposition process, they aren’t something you want to share your nice house with.
Making sure that using rodenticide is a last resort to help solve your pest problems is the easiest way to help limit unfortunate casualties in your walls and floors. However, if you use some sort of bait, remove the target rodent as quickly as possible!
Once the animal is removed, the maggots won’t have a chance to develop into flies and the adult flies will leave to find food elsewhere. Although, since they are just as attracted to rotting and decaying food, dispose of any old food in a sealed can.
In order to be preventive against letting rodents inside, take a look at our piece on the scents that mice hate to keep them out in the first place!
Fruit Past Its Prime Is A Fly Buffet
We’ve all had a fruit bowl sitting out and seen the teeny, tiny visitors that congregate around. Or maybe you’ve left vegetables out on the counter overnight and suddenly small buzzing nuisances are hanging around.
The common fruit fly will swarm around any fruit or vegetable that has started the fermentation process.
These flies are less than a quarter of an inch, usually around ⅛” with red eyes and a dark brown or black body. They would be terrifying if they were any bigger!
The female fruit flies look for fermenting food to lay their eggs so that the larvae can feed once they hatch (here’s a list of what fruit flies are attracted to!)
Those tiny females can lay as many 500 eggs, according to research by the University of Kentucky Entomologist Extension. Their life cycle is only about one week, so they come in great numbers, but with luck, you’ll be able to remove any attractants and be rid of them quickly.
How To Fix It
It’s easy to remove fruit and vegetables you’ve seen fruit flies congregating around. However, if that doesn’t solve the problem, you might be providing another unintentional food source.
Garbage disposals are a prime location for fruit flies with the leftover food matter rotting. Clean out your garbage disposal with citrus or a store-bought cleaner like Lemi Shine Garbage Disposal Cleaner.
Trash cans are another place that fruit flies will rally because of leftover food matter. Wash your cans regularly and sprinkle borax in the bottom of them. The borax will discourage or kill not only fruit flies but any other flies trying to find a food source.
Your mop or mop bucket can provide a habitat for fruit flies if you aren’t thoroughly rinsing out and replacing your mop regularly.
You might need to keep fruit fly traps around if they are still a problem once you remove all the obvious attractions.
Create your own fruit fly trap by filling a cup with apple cider vinegar and adding dish soap. Cover this with plastic wrap and use a rubber band to secure it. Put small holes into the plastic wrap, so once the flies enter, it will be harder to escape.
The apple cider vinegar will attract the fruit flies in and once they land, they will drown because the dish soap has broken the surface tension of the water.
Dirty Drains Are Prime Fly Territory
Have you ever thrown open your shower curtain and seen little flies swarming around and had no idea what they were or where they had come from?
If you’ve seen these flies hanging around your drains in your bathroom tub, sink, or around your toilet, you might have moth flies.
Not to be confused with the nocturnal moths swarming your lights outside, moth flies are also known as drain flies. These drain flies are not great fliers and won’t go far from their source according to Michigan State University Plant and Pest Diagnostics.
Although they are called drain flies, you can find them in any environment that is moist with organic material. This includes rain barrels, toilet tanks, any place where water drips, or even under loose tiles.
These flies are small, at less than a ¼” with yellow to brown coloring and sometimes dark enough to look black. They have tiny hairs that cover their body and wings, which is why they earned the name moth flies.
How To Fix It
The adult female moth fly lays eggs in a moist environment with slime, muck, or algae. The eggs will hatch in 36 to 48 hours, leaving the maggots to feed on any organic material for two weeks before becoming adult flies.
Moth flies can help break down the accumulated waste in drains into something that will wash away, however, if they appear in large numbers, they become a nuisance.
These small flies can leave their feces marks on tile and paint, spread germs around your home, and look unsightly in your otherwise clean home.
Eliminating the drain flies before they develop into flying menaces is the best way to prevent being overrun.
Using a drain cleaner that will flush out your pipes and break down any accumulated crud can eliminate the larvae and eggs. Try using Green Gobbler Drain Clog Remover.
In your bathroom, sometimes no matter how hard you try, there always seems to be a source for flies to be attracted to. Placing eucalyptus or bay leaves in your restroom can add a delightful smell, attractive color, and repel flies. For more options, you can look at our full list of scents that flies hate!
Growing Vegetables Indoors Attracts Flies
If you see flies hanging out around your gardens or potted vegetables, you might wonder what those small insects are. A whole host of flies will congregate on different vegetables.
Cabbage flies prefer cabbage, broccoli, Brussels sprouts, and cauliflower. These tiny gray flies will lay eggs in the fall and overwinter as larvae to emerge as adults in the spring. These maggots feed off the roots and will harm your plants.
There are many types of these root maggots or root flies.
Each one is attracted to different species of vegetables or fruits, such as the apple or hawthorn maggot fly.
The apple maggot flies lay eggs in fruit, which causes the fruit to become misshapen and pitted, says the University of Minnesota.
These flies resemble house flies and are often referred to as biting house flies. The biggest difference between the common house fly and a stable fly is their body colorations. House flies are solid, while stable flies have a spotted back.
How To Fix It
Preventing the flies from laying eggs in the soil is the easiest way to keep an infestation from occurring using Valibe Plant Covers.
A small piece of carpet with a slit will fit around the plant and keep the maggots from being able to get to the roots.
An old toilet paper roll slipped around the small plant and partially buried will also provide an easy barrier to keep the flies away from the roots.
Another method is to use sticky pads around your plants to limit the number of flies freely roaming! You can also place vinegar around your plantsƒ to help mask their scent, which is how flies can sense them in the first place.
Flies Are Attracted To Pet Droppings
If you’ve ever walked your dog and before you could clean up after them and seen a fly zip down and land on the offering, you’ve probably seen a stable fly.
Since these flies, like many others, are attracted to feces when you have any pets that are leaving presents for you around your yard, it can attract stable flies.
Stable flies get their name from hanging around horse stables or other places where animal filth accumulates.
These flies need warm blood to survive since both the male and females of the species feed from mammals.
They like to lay eggs in moist environments such as soiled bedding, manure piles, or even spoiled hay.
These flies resemble a house fly and are often referred to as biting house flies. The biggest difference between the common house fly and a stable fly is their body colorations. House flies are solid, while stable flies have a spotted back.
How To Fix It
Picking up after your pet regularly or cleaning your livestock areas is really the best option here. Just break out that doggy bag!!
Also, if you have kennels, stables, or areas where you keep your pets, try planting or keeping marigolds. Marigolds have excellent repelling properties and will help keep flies curbed and look nice! However, keep in mind that their smell will need to overpower the smell of what your pets leaving behind.
For more options, you can take a look at our piece on plants that can repel flies!
So, yeah. Pick it up!
Flies Love Standing Water
You’ve seen cows, horses, and other livestock trying desperately to get away from insects following them around. These flies that are harassing the local livestock population are called horseflies.
If you have ever been bitten by one, you have a level of sympathy for the horses and cattle!
These oversized flies grow up to 1 ¼” and come in black, gray, or brown. The females reproduce by taking bites out of animals and people and using the blood to lay variable eggs.
Only the females need blood; the male flies do not drink blood. These horseflies can bite through the leather so it’s hard to protect yourself fully.
There are also deer flies, which are larger than your average fly, but not as large as a horsefly. They grow up to ⅓” and bite like a horsefly.
The Entomology Department at the University of Kentucky says larvae of both types of flies will develop in the mud or muck along streams, swampy areas, or areas with seepage.
With up to 1000 eggs being laid by a single female, they can have an explosive population!
How To Fix It
Sprinkling diatomaceous earth across any wet areas or low boggy areas will remove the habitat that horseflies need to lay eggs.
Not only will the diatomaceous earth help with any odor, but it is also a natural deterrent for flies! Diatomaceous earth works by essentially shredding the exoskeleton of a fly once the insect lands on an area with it.
Keeping your grass cut short also removes a potential breeding site since the long grass can trap moisture. Without the moist area under the long grass, horse flies will have to go elsewhere to lay their eggs.
Putting It All Together!
People have been fighting insects since the earliest written works were recorded. Ancient Chinese, Sumerian, and Egyptian scholars even mentioned them in their writings according to North Carolina State!
Knowing that these pests have been a problem for that long shouldn’t discourage you. No matter what type of flies you have in your home, trying a combination of these methods will help you combat any encroaching fly hoards. The more methods you can implement, the faster and more thoroughly you’ll handle your fly problems.
Ideally, you remove all fly lures and don’t have to deal with the pesky air invaders anymore.
When all else fails, don’t forget to grab your trusty flyswatter! If you’d like a step-by-step, take a look at our guide on the things you should do once you find a fly in your house!
Graham-Smith, G. S. “Observations on the habits and parasites of common flies.” Parasitology 8.4 (1916): 440-544.
Thomsen, Mathias, and Ole Hammer. “The breeding media of some common flies.” Bulletin of Entomological Research 27.4 (1936): 559-587.
Dodge, Harold R. “Identifying common flies.” Public Health Reports 68.3 (1953): 345.
Greenberg, Bernard. “Flies and disease.” Scientific American 213.1 (1965): 92-99.
Zack is a Nature & Wildlife specialist based in Upstate, NY, and is the founder of his Tree Journey and Pest Pointers brands. He has a vast experience with nature while living and growing up on 50+ acres of fields, woodlands, and a freshwater bass pond. Zack has encountered many pest situations over the years and has spent his time maintaining and planting over 35 species of trees since his youth with his family on their property.
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