When you think of household pests in Maryland, drain flies likely don’t come to mind first. Drain flies are a pest most people have encountered before, but their small size and generally harmless nature make them pretty forgettable to most homeowners.
However, an unchecked drain fly infestation can be pretty unpleasant and put your health at risk.
This article will uncover everything there is to know about these disgusting creatures and provide you with seven proven ways to get rid of drain flies for good.
What Are Drain Flies?
Drain flies, commonly referred to as moth flies, are small flies that are known to inhabit drains, gutters, and wet garbage cans. They are moth-like in appearance and have hair on their bodies. They are typically gray in color and have two large wings with spots on them.
These flies reproduce quickly in moist organic matter, such as sludge or scum inside pipes, making them difficult to eliminate once established. While they don’t bite, their presence indoors is a clear sign of a moisture or drainage issue that needs attention.
How Do Drain Flies Differ from Fruit Flies?
Drain flies and fruit flies are often mistaken for one another, but the two have several key differences. They are drawn to drains and other wet and damp places, while fruit flies are attracted to meat, dairy, garbage, and other places where they may find food sources.
These flies are also larger than fruit flies, as fruit flies are only about 1/8th of an inch in length. In addition to being smaller than drain flies, fruit flies don’t have the same furry appearance that drain flies have.
Why Do I Have Drain Flies?
You may be seeing drain flies in your home for a few different reasons. These pests are attracted to standing water and moisture, so seeing these flies in your home may be a sign that you have a clogged drain.
You may also notice drain flies in rarely-used toilets, sinks, or leaking pipes. If you go out of town for a while and return to find drain flies in your home, it may be because the water in your sink, pipes, and toilets was stagnant while you were gone.
Signs of Drain Flies
When it comes to spotting a drain fly infestation, there are several signs to look for, including:
- Clusters of flies near sinks or tubs at night: Drain flies are nocturnal and often rest on nearby walls when not active.
- Tiny moth-like insects emerging when you turn on a faucet: This is a giveaway that the source is inside the drain.
- Slow-moving or clogged drains: Organic buildup inside the pipes often accompanies drain fly infestations.
- Gel-like film inside pipes: This biofilm is where the flies lay eggs and larvae develop.
- Black specks or debris around drains: These may be dead adult flies, waste from larvae, or buildup that signals a breeding site.
- Recurring flies despite cleaning visible surfaces: This usually means larvae are hiding deeper inside the drain system.
7 Ways to Get Rid of Drain Flies
If you have been seeing these irritating pests in and around your home, here are some helpful tips to get rid of them:
1. Clean Your Drains with a Brush
Cleaning your drains using a drain brush can not only keep drain flies away, but it can also help keep your drains from clogging and keep water moving smoothly through the pipes. A stiff, long-handled brush can reach the gunk where eggs and larvae often hide.
Scrub the sides of the pipe thoroughly to remove biofilm buildup, which is the primary food source and breeding ground for drain flies.
2. Use Drain Cleaner
Certain drain cleaners, including Drano and foaming enzymes, can effectively kill these flies.
Enzyme-based cleaners are particularly effective because they digest organic matter inside the pipes, removing the breeding ground instead of just killing adult flies.
Chemical drain cleaners, such as caustic or oxidizing products, may work faster, but enzyme-based cleaners are safer for pipes and septic systems.
Best Drain Cleaners for Drain Flies:
- Bio-Clean Drain Septic Bacteria (enzyme-based, safe for long-term use)
- Green Gobbler Enzyme Drain Cleaner
- Invade Bio Drain Gel (used by pest control professionals)
- Drano Max Gel Clog Remover (fast-acting chemical option)
- Roebic Laboratories K-87 Drain Build-Up Remover
3. Dump Boiling Water Down Them
If you’d rather avoid using drain cleaner to get rid of the flies in your home, you can try pouring boiling water down the drain to kill these pests. For best results, repeat this process two to three times a day for a week. The hot water loosens grime, kills larvae, and flushes away organic buildup.
4. Use Vinegar and Baking Soda
Making a concoction using vinegar and baking soda and pouring it down the drain can also be effective in killing them. The bubbling reaction helps dislodge gunk along the pipe walls while the vinegar kills bacteria. For maximum effectiveness, follow with hot water after 10–15 minutes to flush away loosened debris.
5. Create a Bleach Solution
Similar to vinegar and baking soda, pouring bleach down your drain may also help get rid of the other flies as well. Bleach works quickly to kill eggs and larvae, but it doesn’t always remove the organic matter where flies breed.
Use bleach with caution, as it can be harsh on pipes and should not be mixed with other chemicals.
6. Use Drain Fly Traps
Using drain fly traps can be another good option if you are dealing with these pests in your home. These traps can either be purchased at the store or made using a DIY approach.
Commercial sticky traps placed near sinks, tubs, or drains can help catch adults, while homemade vinegar traps can reduce their population. Traps work best when used in combination with cleaning methods that target larvae.
7. Call an Exterminator
Whenever you’re dealing with a pest of any kind, your best bet is to contact an exterminator right away. Even if you think you’ll be able to handle the problem on your own, you may end up making the problem worse or, at the very least, wasting money buying drain fly traps and solutions to kill them.
A trusted exterminator will be able to assess the infestation and recommend a plan of action to get rid of it for good. Exterminators often use commercial-grade bio-enzymes and specialized equipment that homeowners may not have access to.
Are Drain Flies a Health Hazard?
While drain flies are not known to bite or sting, they can still pose minor health risks. Their larvae feed on decaying organic matter, which may contain bacteria. In large infestations, the constant presence of adult flies can contribute to unsanitary conditions, especially in kitchens or food prep areas.
People with asthma or allergies may also experience irritation from prolonged exposure to drain flies or their breeding sites.
In short, they are not dangerous like mosquitoes or cockroaches, but they are a nuisance and should be dealt with promptly.
Where Do Drain Flies Usually Occur?
Drain flies thrive in areas with standing water and organic buildup. They are most commonly found in:
- Kitchen sinks with food residue in the pipes
- Bathroom sinks, tubs, and shower drains with soap scum buildup
- Basement floor drains or sump pump pits
- Utility rooms with rarely used drains
- Grease traps and commercial kitchen drains
- Outdoor areas such as gutters, storm drains, or compost bins
If you notice them in one room, chances are there’s another hidden breeding site nearby.
You can avoid drain flies in Maryland by cleaning your pipes regularly and keeping your home clean. However, when drain flies do strike, you may need to call a qualified exterminator if you can’t handle the problem on your own.
FAQs
Can Drain Flies harm humans or pets?
While they are creepy-looking and unpleasant to have in your home, they are typically not harmful to humans or pets and are not known to be particularly unsanitary.
Where do Drain Flies come from?
They breed in clogged gutters, drains, and other areas where standing water can be found. If you are noticing them in and around your home, you may want to check these places for any signs of a breeding area.
How effective are enzyme-based drain cleaners against Drain Flies?
Enzyme-based drain cleaners may be effective in getting rid of drain flies, but it is always advisable to seek the help of a pest control professional rather than trying to get rid of any pest yourself.