June 1, 2026
Beyer Plumbing Technician at work on a bathroom drain.

Noticing tiny, hairy, moth-like creatures becoming your new bathroom companions while you’re brushing your teeth or taking a shower? These little pests go by many names, most commonly known as drain flies, they are also called moth flies, sewer flies, and filter flies.

 

Whatever you choose to call them, one thing is certain – when they take up residence in your bathroom, they may be a sign that your drains or pipes need attention. Although they are generally known as weak fliers, have extremely short life spans (adults live around 12 days), and can’t cause much physical harm to us – they do not bite humans or animals – their presence can indicate that your pipes may need some upkeep.

 

According to the U&A Division of Agriculture, drain flies feed on and breed quickly based on a diet of organic matter that can easily be found in:

 

  • Household drains
  • Wet compost areas
  • Clogged gutters
  • Potted plants with wet soil and standing water

 

Addressing a potential infestation in a timely manner is important because recurring drain flies may point to hidden buildup, standing water, leaks, or other plumbing issues.  

 

Methods for Removing Drain Flies

 

Tiny drain fly hairs aren’t just for looks, they have water repellent properties, which makes drowning them by running your sink or shower ineffective. Pouring insecticide down your drain won’t work either; this can cause damage to your septic system. 

 

To effectively remove drain flies, first identify the exact area of infestation and make sure the flies are not coming in from an outside source. 

 

This can be done by taking a glass jar or clear plastic container and covering your drain opening to trap a few emerging adults. Return after a few hours, if you have correctly deduced the source you will see plenty of flies swarming the trap.

 

From there, the best methods to remove drain flies generally focus on thoroughly cleaning and sanitizing the infested drains:

 

  • Avoid bleach, as drain fly larvae have generally shown resistance to its use. 
  • Foaming enzyme-action cleansers that can break up soap scum and algae buildup have proven especially useful in clearing out breeding sites.
  • A drain snake or stiff bristle brush will also aid in deep cleaning sinks and basins.

Can a Plumber Remove Drain Flies?

Small as they are, drain flies are notoriously tough to root out, and even a deep clean may not completely solve the problem.

 

If you’ve tried every method of sanitizing your home’s pipes and drain flies are still populating, it may indicate a broken pipe, water leak, or drain sludge that can not be easily detected or fixed with traditional remedies alone.

 

Drain flies may be weak with short lifespans, but they are attracted to deep buildup in drain pipes and AC systems, and larvae can be continuously harvested by the hidden nasty stuff lurking underneath what’s in plain view. 

 

With further investigation, you may find that high pressure drain cleaning or a leak repair may be the answer to the issue.

 

Call Beyer Plumbing Today

 

Let Beyer Plumbing take a look for you! We provide professional and efficient repairs and drain cleaning throughout South Texas, including San Antonio, New Braunfels, San Marcos, Helotes, and surrounding communities. 

 

Our licensed plumbers ensure your pipes and the overall health of your plumbing systems are taken care of so pesky drain bugs stay gone permanently.

 

Ready to solve your drain fly problem and never set sight on one again? 

 

Scheduling your home service is simple! Our licensed and certified technicians are ready to assist you.

 

Call us at (210) 809-6355 or schedule online today and say bye-bye to drain flies for good.

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