Skip to Content

6 Reasons For Basement Flies (Easy Solutions)

I can think of very few things worse than walking down into your basement and having to constantly swat away flies as you get what you need.

Unfortunately, these flies tend to appear when there are hygienic issues happening in the basement that need to be dealt with immediately. Fear not, as I have provided you with easy-to-implement solutions for the most common reasons you might be getting basement flies.

1. Stagnant Pools of Water

Stagnant water can gather around your home for a variety of reasons. If your house has been built on a slope, then it is possible for water to drain down towards your basement. Often, on a slope, this will be a walkout or daylight basement. Your downspouts can also collect water at their exit points which can accumulate quickly as well.

Stagnant water can also accumulate after a period of heavy rainfall, after you have watered your garden, or even after washing your car.

Sewage hatch in a dirty puddle on the asphalt. Night yellow brown light

This standing water creates the opportunity for organic matter to accumulate, which creates an attractive breeding ground for flies to feed and reproduce. These flies will then be able to enter your basement and create a truly annoying and uncomfortable situation.


Your first step is to identify the stagnant water source, and then eradicate it as soon as possible.

It is important to empty out any buckets used for cleaning or gardening immediately, and turn them open side down so that any rain water can not accumulate in them and attract flies.

Avoid overwatering your garden so that pools of water don’t accumulate. Use a watering can rather than a hose as less water will be expelled.

You need to make sure that any downspouts are directed as far away from your home as possible so that water is not all drawn towards one spot near the foundation.

2. The Presence of Trash

If you keep your trash in the basement before you take it out to the curb to be collected, you may be attracting flies and other unwanted critters into your basement.

GrandLifeBrands PREMIUM Odor Eliminator - dead rodents, FLOODING SMELL, pets, cat litter, garbage, skunk, urine, feces, smoke - REMOVES, NOT COVERS UP -odors (English/Español/Français)

Any decaying food in the trash will attract these creatures and create a fruitful breeding ground for them. Once their offspring hatch, the larvae grow by eating the same rotting food in the trash, and the problem multiplies like a run-away train.


There is a really simple fix to this problem. Either keep your trash outside and not in your basement or make sure your trash bag is in a trash bin that has a lid that can be tightly sealed. This will prevent any flies from entering the trash bag and reproducing, causing an irritating fly infestation.

If you have had a fly infestation, then once you have removed the trash from your trash can, it is advised to give it a thorough clean on the inside and exterior. You can use any kind of cleaning detergent, but experts advise creating a solution of vinegar and warm water for a truly effective cure. Make sure the trash can is completely dry before filling it again.

Since flies are attracted to your rotting leftovers, try to dispose of them either in your garbage disposable or in a separate plastic bag that you can easily seal and dispose of in an outside bin.

3. Animal Feces

Flies are attracted to anything rotting or decaying, so your golden retriever’s daily droppings festering in the summer heat make a perfect haven for them to set up camp and reproduce.

Your dog might decide the best place to do his business is right outside the basement window, which creates a perfect opportunity for the flies to swoop right in. This is a particular issue if your windows are left open to create a draft through the house for ventilation.

Fishnure 8 lb Sustainably sourced Odorless Organic Humus Compost Fertilizer That enhances Soil with Living microbes for Herb, Vegetable, Flower, and Fruit Gardens - Naturally Increases biosorption

Sometimes accident’s also happen inside the house, when you are not aware of it. These ‘hidden’ droppings create a warm breeding ground for flies, which can spread around your home quickly.

Keeping your kitten’s litter box in the basement might have sounded like a great way to keep it out of sight, but the feces will attract flies into the space immediately.


There is no easier solution than to simply keep your yard clean. Try not to let the feces accumulate too much so that it will take you less time to pick it all up and it will not be standing for long enough for flies to reproduce.

Cleaning up and replacing the kitty litter is vital if you want to avoid continuous infestations of flies in your home.

If you assign just a few minutes every day to clean up after your pet, it is a simple way of preventing the buzz of flies in your basement.

4. Undiscovered Animal Carcasses

You might have noticed an odd smell in your basement accompanied by a lot of flies zooming past you as you do your laundry. I’m sorry to tell you this, but there might be a dead animal somewhere in your basement, and unfortunately, it might not be that easy to find its location.

A hole in the outside wall, floor, or the drains, might have invited an unwanted rodent or other small animals into your basement. Without an escape route and sufficient food, this animal could have become trapped and died behind your drywall or even in your pipes.

Closeup dead mouse on gray floor in an apartment house

Flies are attracted to decaying matter as they feed off of it. Once the flies find this unwanted carcass, they are able to breed quickly and can quickly become a health risk for your family.


The first thing you should do is inspect any openings in your basement for animal carcasses and remove them immediately (using the correct protective equipment, such as latex gloves and masks, to protect yourself from any diseases the animal might have been carrying).

Place animal carcass in a plastic bag, tie it up without letting much of the air escape, and then place that bag into another plastic bag and seal it tightly. Throw the bag away in a closed trash can away from your home, and wash your hands thoroughly.

Once disposed of, clean the area thoroughly with disinfectants. Depending on the severity of the situation, you may want to have some fans blowing around the area, while keeping your basement doors and windows open, to remove the odor from the basement.

5. Dirty Drains

Certain flies are known to be attracted to the dirt that builds up in the drains around and in your home. A a dirty drain in your kitchen, where the flies are attracted to the food build up in the drain, or in your basement can quickly form a breeding ground for flies.

Baking soda in a spoon over a dirty dishwasher sink


Simply put, in order to prevent flies from coming to your dirty drains, you need to make sure your drains are kept clean.

A great home remedy is to combine vinegar and baking soda to make a solution. Pour this down your drain, and the foaming solution will remove any built-up dirt that might be clogging your drain. Use a piping brush to scrub down the drain even further. A great easy-to-do tip is to pour boiling water down the drain a few times a week.

If the flies really aren’t leaving, then do yourself a favor and get some Drano Max Gel Drain Clog Remover and Cleaner for Shower or Sink Drains (amazon link) as it can instantly unclog your drain.

The experts recommend that you stay away from pouring pesticides down the drain as the water goes back to the main source (perhaps a dam or river), which can harm any living things that might be living there.

In your kitchen, avoid putting leftover bits and pieces of food from your plate down the drain. Rather scrape them off entirely into a plastic bag, which you should seal and dispose of immediately.

6. Stored Food.

As we all know, a basement is a great place to store all the things that you don’t want to be visible or have space for on the main floors. However, if you need to keep any spare food in your basement, you could be at risk of attracting flies into that area as they are attracted to food.

The seal of the containers might become compromised for a number of reasons, which can create the opportunity for flies to feed and reproduce. Your kids might have taken a cookie out of the container and not closed it properly afterward, or your containers might just be getting old and not sealing as efficiently as before.

Fruit flies have gathered to feed on a discarded watermelon that is on the green grass

People also convert their basements, or at least part of their basements, into root cellars and store fresh produce. The environment is typically well-controlled, but all you need is one potato going bad at the bottom of the crate and it can become a problem.

It does not matter the cause, or how large the opening is, flies only need a tiny entryway into a container in order to infest it.


Unfortunately, if you see your food has been infested with flies, you need to dispose of it immediately since these creatures can carry a handful of harmful diseases.

It is really important to store any food in airtight containers to avoid any possible infestations. The Airtight Food Storage Container Set CINEYO (amazon link) is a super affordable option that can keep a variety of food fresh and safe from pests.

In order to avoid having this extra food available for flies to devour, try only buying your food in smaller quantities so that it won’t be laying around for too long. In root cellars, have a system of checking for bad items and keep a close watch on the ventilation.

Make sure that any boxes or containers have not left behind any crumbs on the shelves as these too can attract flies.


Was this helpful?

Amazon and the Amazon logo are trademarks of, Inc, or its affiliates.