Are Drain Flies Harmful

Last Updated on February 28, 2023 by admin

Have you noticed any small, unusual-looking flies around your sink or drainage system? These may be drain flies, and even though they are not very dangerous, they should be investigated further.

Drain flies

A drain fly is an insect that lives in unclean places, including drains. They are known by various other names, including sewer gnats, sewage flies, moth flies, and filter flies. Identifying features of these flies include their habitat (sewers and drains), their winged appearance, the color black, brown, or gray, and their small size (usually smaller than a housefly). Its diet is not desirable, consisting of sewage and other forms of organic matter.

Are drain flies harmful?

Drain flies lay their eggs in organic matter found in sewers and drains and become adults within a week. It is likely that when you see these creatures emerging from your drain system, you first think to yourself, are drain flies harmful? Drain flies are not harmful to humans or buildings when few. It is only when they congregate in large numbers that trouble can begin. A drain fly, for example, carries bacteria under where they live. This, along with their unsightly presence, especially in kitchen areas, can be a nuisance to you, your family, or your clients.

Drain flies typically do not pose a health threat to humans, even if they originate from places we would not want to be near. A 2015 study on Psychodidae infestations from Cambridge found cases where specific species were the leading cause or trigger for some diseases. These include myiasis, microfilaria, and asthma.

How can drain flies be eliminated naturally?

Add one cup of white vinegar, one cup each of salt & baking soda. Permit it to do its job during the night, and then the following morning, clear the drain using hot or warm water. The drainage will be sanitized, and the flies & their eggs will be eliminated.

Can toilets cause drain flies to appear?

In the accumulation of pipes, drain flies reproduce. Although they are less likely to be found in toilets, they may be getting through the leaky seal between both the toilet & sewage flange. This could mean they are flying upward while reproducing lower to the ground in the pipe.


According to the American College of Pediatrics, myiasis is an infection caused by parasites such as fly larvae, which require a host to develop. Like a science fiction movie, the larvae typically dig into tissues and feed on them, causing lumps, burning, itching, and possibly bacterial infection. Although most domestic drain flies don’t cause this disease, the 2015 study revealed that Clogmia albipunctata causes this disease as an opportunistic agent.

The Microfilaria

Another tropical variant of the standard drain fly is Sycorax silica. In addition to feeding on blood, it transmits parasitic nematodes. It is explicitly known as Sycorax silica, a vector of microfilaria.

Microfilaria is parasitic Onchocercidae nematodes in an early stage. Microscopic worm-like organisms, these invading creatures thrive inside the bodies of their hosts. They are essentially found in the tissues or circulatory system. The adult nematodes periodically release their offspring, the microfilariae, into the blood so that they can be picked up by another host, the bloodsucker Sycorax silica. Microfilariaemia refers to the presence of microfilariae in your body. A fever, pain, and extreme swelling may result in some regions of the body, as well as many other painful symptoms.

The Leishmaniasis

Blood is also the food source of another tropical drain fly, the Phlebotomies. This way can transmit tropical diseases, particularly leishmaniasis, another disease caused by parasites. Leis mania parasites can enter the body through the bite of a fly. As a result, it can manifest in three ways: via skin ulcers, ulcers in the skin, mouth, and nose, or through fever, an enlarged spleen and liver, and a low red blood cell count. Leis mania species cause human infections in more than 20 species.


Although it may seem unlikely, these annoying pests can cause bronchial asthma. Many of them can easily blow them toward houses if they grow in large numbers. It is possible that inhaling the dust from these disintegrating small flies can cause asthmatic reactions.

How do you know if you have a drain fly infestation?

An infestation of drain flies can strike without warning, which is inconvenient for homeowners and business owners. The best way to prevent an infestation is to learn how to spot the signs. If you’re trying to tell a drain fly from another type of insect, brush up on your identification skills. One way to determine if you have a drain fly infestation is to put sticky tape over a part of the drain entrance and observe whether they stick.

It’s worth arranging a drain CCTV survey from a professional if you suspect an infestation of drain flies. The specialist will feed small cameras into your system to find the source of your drainage problems, confirming whether drain flies are to blame for them and the extent of the problem.

How to get rid of drain flies?

  • Ensure you have a drain infestation by arranging a professional CCTV survey and remember to check your septic tank as they are also known to inhabit here.
  • By cleaning drains and sinks with hot water, brushes, or drain cleaners, you eliminate the flies’ food source, disrupt their breeding ground, and disrupt their ability to feed, breed, and flourish.
  • You should consider hiring a professional pest clearance company if you haven’t been able to eliminate the problem with home remedies. They can correctly identify where the pests are located and eradicate the problem for you.
  • Inform your neighbors about your infestation; they may need to have their drains checked to improve the drainage health of the entire neighborhood.

Final thoughts

Are drain flies harmful? Tropical drain flies pose a more significant threat to our health than the flies we often see around our homes. However, they are not deadly. Of course, everyone does not want to live near dirty sewer insects. As a result, getting rid of them is still the best option for your peace of mind.

Apart from this, if you want to know about gnats in bathroom, then visit our Home Improvement category.


Drain flies: are they harmful?

Humans are not harmed by drain flies, also known as moth flies and sewer flies. The drain fly is relatively harmless compared to other fly species in Canada. Drain flies do not threaten disease transmission; however, they are known to trigger bronchial asthma in susceptible people.

Can drain flies transmit diseases?

They are small and gray. Their decaying bodies can cause allergic reactions, but they do not bite, sting, or spread disease. They can also transmit bacteria from trash, decaying vegetables, and fruit.

Where do drain flies come from?

The drain flies do not enter the drains or pipes; instead, they enter the gutters when they smell the organic matter they need to breed. Their small holes allow them to enter your home. They tend to congregate around sinks and drains in the evening when they are most active.