Have you noticed little insects hovering around your kitchen, even when you take out the trash regularly? Or little flies milling around your bathroom? If so, you probably have drain flies, small insects that like to live in rooms with drains, as the name suggests. The scientific name Psychodidae can apply to all types of drain flies that live near water of varying temperatures. Here’s what you need to know about identifying drain flies and getting rid of them.
What Are Drain Flies?
Drain flies are small insects that live in areas with drains or pipes. They are a very common household pest and can be found in other commercial areas with drains, like water treatment plants, locker rooms, or places with stagnant water. Here’s what you need to know to identify them.
What do drain flies look like? Drain flies are very small, measuring between ⅙ and ¼ of an inch long. They have small, hairy bodies that are brown-gray or black that have a fuzzy appearance. Their wings are also hairy and shaped like leaves. When a drain fly is at rest, the wings sit over the body like a roof for protection. Drain flies are often spotted just resting on walls or ceilings, not flying around, but they will make short, hopping flights to a different location if they are disturbed.
What do drain flies eat? Drain fly larvae feed on decaying organic matter, like algae, bacteria, and fungi. They get their food from the film or slime that builds up in drains, pipes, or traps. They may also eat other microscopic plants and animals found in filters around sewage plants. Adult drain flies have a diet consisting of polluted water and flower nectar.
Types of Drain Flies
The term “drain fly” can apply to three different groups of insects, but it’s usually used to refer to the one described above, also called the moth fly. Technically, fruit flies and phorid flies can also be drain flies since they, too, breed and feed in drains or sitting water and eat decaying matter. Even so, the moth fly is the insect most closely associated with being a drain fly.
Where Do Drain Flies Live?
Drain flies seem to appear quickly and out of nowhere. While they can live anywhere with drains or pipes, some of their favorite spots include:
- Bathrooms
- Kitchens
- Agricultural facilities
- Commercial washrooms and locker rooms
- Sewage plants
Within these places, they breed in drains or taps, with the larvae living in the film inside. They also breed in:
- Dirty trash cans
- Saucers underneath potted plants
- Condensate pans under fridges and freezers
- Septic tanks
- Rain barrels
- Moist compost piles
- Toilet tanks
Drain fly life cycle. Drain flies complete their life cycle between 21 and 27 days. Females lay eggs in a damp place, like a drain, usually depositing between 15 and 40 eggs at a time. These eggs hatch within two days and turn into larvae. The larvae grow between 9 and 15 days, so this is the longest part of their lives. The water temperature determines how long they stay in this stage.
Next, they go into a pupal stage for a day or two. Adult flies then emerge from the pupae. Females live up to seven days, males less. They are nocturnal insects that feed and lay eggs at night.
Signs You Have Drain Flies
During the day, you’ll notice drain flies resting on the wall since they aren’t good fliers. At night, when they are active, they will congregate towards light sources, like lampshades. They will also feed and breed at night, so you’ll see them near food sources or breeding areas. You’ll most likely see only a few at a time, as you only rarely see drain flies in large numbers at once.
It’s easy to miss the larvae since they’re small and might be hidden. If you think that you have drain flies, try covering the suspected breeding area with a glass or plastic cup with a little vegetable oil inside. This will trap any flies that emerge and let you know this is where the drain flies are coming from.
Why Do You Get Drain Flies?
Drain flies are very common and can breed anywhere with stagnant or dirty water. They are usually only a temporary problem and happen most often when your household is inactive, like when you’re away on vacation. When household activity picks up again, and water starts moving, the drain flies usually disappear.
Health Risks of Drain Flies
Drain flies don’t cause any damage to your home or plants, but here’s what you need to know about these pests and your health.
Do drain flies bite? Drain flies don’t bite or sting people or animals. However, if they die in your home, their decaying bodies can cause allergic reactions in some people. People with asthma may have trouble breathing because of the dust and fragments from their bodies, as well.
Drain flies may cause a health hazard by carrying pathogens to places that need to stay clean. Drain flies can carry bacteria from the trash or drains to areas of your home that should be sterile, like where you prepare food in the kitchen. They can also be a nuisance when they fall or land in your food when they hop around your kitchen or living room.
How to Get Rid of Drain Flies
There are a few different ways to get rid of drain flies, but first, you must identify the source. Once you’ve identified the source, using the trick mentioned above, you can eliminate drain flies easily. The first is to clean the drain or area where they are breeding thoroughly. If the area is clean, the larvae won’t have a food source to continue growing and developing. You can use bleach or commercial cleaning sprays to clean areas like your bathroom or kitchen.
There are many aerosol pesticide sprays on the market for flying insects, but these will only kill active drain flies. If you choose to use them, you must find products that are marked safe to use indoors. Using these sprays isn’t encouraged for controlling drain flies, as the key is to cut off their breeding ground. The best way to control drain flies is by preventing them in the first place by regularly cleaning your drains.