Drain flies, also called moth flies, belong to the family Psychodidae and get their name because they often breed in drains. They are found throughout the United States and can become an annoyance in homes, sometimes appearing suddenly from sinks and bathtub drains. They can breed in tremendous numbers in sewage treatment plants and then be carried away by the wind to nearby buildings, where they can crawl through fly screens.

Drain Flies in Florida

Florida’s warm and humid climate provides the perfect environment for drain flies to thrive. These pests are often found near septic tanks, sewage systems, and clogged drains, making them a common issue for residents. Drain flies are weak fliers; when encountered, they are often found crawling on walls and other surfaces.

What Do Drain Flies Look Like?

Adult drain flies are small insects with hairy bodies and long antennae, giving them a moth-like appearance. Their wings are covered in fine hairs, making them appear fuzzy. Typically, they are gray or black and measure about 1/8 inch in size. Despite their wings, they are weak fliers and often rest on walls near their breeding grounds. 

Signs of a Drain Fly Infestation

A drain fly infestation often starts subtly, with easily overlooked signs. You might notice adult flies resting near sinks, drains, or walls, particularly in bathrooms and kitchens. Their larvae or pupal stages can sometimes be spotted in drains, especially in areas with accumulated gelatinous organic material.

Another common indicator is the sudden presence of small, weak fliers around drain pipes, bathtubs, or other moist areas. You may also observe persistent flies near septic tanks or clogged sinks, where they are drawn to the moisture and organic matter. If you detect any of these signs, it’s important to address the issue quickly to prevent the infestation from escalating.

Habitat, Diet, Life Cycle & Behaviors

Where Do Drain Flies Live?

Drain flies develop in muck or gelatinous material that accumulates in sewage disposal beds, septic tanks, moist compost, or dirty garbage containers. They may also emerge from drains of sinks or bathtubs, tree holes, rain barrels, moist organic solids, or bird nests that have accumulations of fecal material. Drain flies gather, mate, and lay eggs in moisture or standing water. The slimy film that forms in sewers and drains is a favorite breeding spot.

Diet

Drain flies feed on decaying organic matter and other organic material found in sewage, drains, and stagnant water. Their larvae consume this material, breaking it down further as they grow.

Life Cycle

The life cycle of drain flies includes four stages: egg, larva, pupal, and adult. Female flies lay their eggs in gelatinous organic matter in drains or other moist areas. The larvae feed on the decaying material before pupating. This cycle completes in about two weeks, allowing infestations to grow rapidly if left unchecked.

Behaviors

Inside structures, drain flies are strongly attracted to light and can be found on glass windows, doors, lamps, and indoor lighting. They are most active during the evening and prefer resting on walls or near their breeding grounds.

Are Drain Flies Dangerous?

Drain flies do not bite people or animals or do damage to structures or plants. However, because these flies originate from filthy sources, they have the potential of being mechanical vectors of diseases. Populations of these insects can become a nuisance in homes, and their presence is almost always linked to a clogged drain. In residential homes, the most common breeding sites are bathroom drains.

If you are dealing with a drain fly problem on your property, – contact your local fly control experts.

How to Get Rid of Drain Flies?

Eliminating a drain fly infestation requires focusing on their breeding grounds and removing their food sources. Start by thoroughly cleaning your drains to eliminate the organic buildup that attracts these pests. Using a drain cleaner or a combination of baking soda and vinegar can effectively break down the slimy material where they lay their eggs. Next, inspect your plumbing for leaky pipes, as repairing these can significantly reduce the moist conditions drain flies need to thrive. 

It’s also important to address any areas with standing water, such as clogged sinks or outdoor puddles, as these can serve as additional breeding grounds. For persistent infestations, consider contacting our professional residential fly control service; we can offer a thorough and targeted approach. Additionally, installing tools like our commercial Lumnia insect light traps can help monitor and reduce adult fly populations, keeping your home safe.

Drain Fly Prevention Tips

Preventing drain flies begins with regular maintenance of areas prone to moisture and organic matter. Clean your sinks, drains, and pipes frequently to prevent the buildup of decaying materials that these pests thrive on. Avoid allowing standing water to accumulate in or around your home, as this creates ideal breeding conditions. 

Be proactive about inspecting and repairing leaky pipes or other plumbing issues that might create moist environments. To further reduce the risk of infestation, screens or covers on septic tanks and sewage systems should be used to block entry points for adult flies. 

Lastly, ensure that trash bins and compost containers are sealed tightly to prevent access to decaying organic material.

Do You Have a Fly Infestation Problem? We Can Help.

Acting quickly is essential if you’re struggling with a drain fly infestation. While DIY methods may provide short-term relief, fly pest control ensures a comprehensive solution. We also provide resources like information on types of flies in Florida to help you stay informed about pests in your area. Don’t let drain flies overrun your home—contact us today for reliable and effective pest control solutions.

FAQs

What causes drain flies?

Drain flies are typically caused by moist environments and organic material where they can breed. They thrive in areas like clogged drains, septic tanks, and sewage systems, where they feed on decaying organic matter and slimy buildup. Standing water or leaky pipes can also create ideal breeding grounds for these pests.

Do drain flies bite?

No, drain flies do not bite. These insects are harmless to people and pets as they cannot pierce the skin. However, they can still become a nuisance and potentially spread bacteria from the filthy environments they inhabit.

Are drain flies attracted to light?

Yes, drain flies are attracted to light. Inside homes, you’ll often find them near windows, lamps, or other light sources. Their attraction to light can make them more noticeable when populations grow.

Are drain flies and fruit flies the same?

No, drain flies, and fruit flies are different insects. Drain flies, also known as moth flies, have hairy bodies and thrive in moist environments, particularly near drains and sewage systems. Fruit flies, on the other hand, are smooth-bodied and are typically found near decaying fruit or sugary substances. While they may appear similar at first glance, their breeding habits and habitats are distinct.