Drain Flies

Drain Flies Scientific Name: Psychoda alternate

Facts about Drain Flies

Sometimes the most innocent looking pests can be the most problematic. With their small size and fuzzy wings, these flies are often mistaken for small moths, but drain flies can cause huge problems in household or commercial drains as well as increase health risks in asthmatics. Making their homes in shallow standing water or in moist corners, the drain fly is difficult to detect at first thanks to its size and non-menacing appearance. Creeping into kitchen, bathroom and outdoor drains and pipes to reproduce creates a huge nuisance for humans; flushing out drains and getting rid of standing water are just a few of the procedures necessary to eradicate Drain flies pests from your home.

Drain Flies Identification

A mere 1/6” long, the drain fly would appear smaller than a chocolate chip sitting in your drain. Covered all over in dark and fuzzy hair, drain flies rely heavily on their fuzzy antennas to locate food. Each part of the antenna is an individual ‘tongue’ for the fly to help them determine what is in their immediate surroundings. Once the drain fly reaches their adult 1/6” size, it becomes clear that their wings are disproportionately large compared to their small body. Although the large wingspan should make the drain fly a strong flier, the difference in body and wing size actually make the drain fly clumsy and only able to fly in short distances. For the most part the drain flies will rely on crawling from one place to another, and once they find a suitable drain to nest in they are unlikely to leave of their own will.

Drain Flies Habitat

The name should give a generous clue as to where Drain flies reside. Drains and pipes with shallow water are ideal for this moisture-loving insect. When pipes have gone unused for a long period of time (i.e. winter, long vacations, etc.), the drain flies make themselves at home, feeding on leftover liquids or moist solids in the pipes/drains and sewers.

Some of the most common areas to find drain flies in your home are:

  • Kitchen drains, especially if no garbage disposal is present
  • Bathroom sinks – most people don’t clean drains unless they become clogged
  • Showers/Bathtubs – make sure to let shower curtain dry completely in between uses and cleanse drain often
  • Unused or stagnant pipes that have been shut off for a period of time
  • Indoor houseplants

One of the most frustrating aspects of the drain fly is their size; even as a full-grown adult, the drain fly is able to squeeze through the small holes in screen doors and cracks throughout your home or commercial buildings. Sewer lines under buildings are also a major habitat for drain flies; the waste products and decay make it a perfect nesting ground for newly hatched larvae. Feeding on decaying food or human waste makes the drain fly a possible carrier of serious diseases into homes.

Life Cycle of the Drain Fly

Three weeks. That is all the time the drain fly has to live, and yet they make good use of that time in terms of reproduction. In a typical drain fly litter there are between 30 and 100 eggs, each of which are laid in shallow water and can hatch in as little as three days. Once born the primary calling for a drain larva is to feed. The larva is dependent on the food around it, as it does not travel any distance. Ideally, the larva will feed on decaying food that has become liquefied or human/animal waste; without this food source the larvae will die. The larva stage last about two weeks and then transforms from a gray worm-like creature into a pupa for the next two days. After those short 48 hours, the adult drain fly will emerge and begin reproducing almost immediately. From this short timeline it becomes clear how drain flies can pose a problem to the home or building that houses them. With such a short turnaround, 100 identical flies replace one fly; it makes it difficult to get rid of them all at once.

Drain Flies and Humans

The greatest threat that drain flies pose to humans is the risk of being inhaled. Unlike other flies that are large enough to be avoided, the drain fly is miniscule in comparison. It is quite possible in houses that have a drain fly problem to inhale all or parts of the drain fly directly into the lung. While many people may not notice this addition to their oxygen, asthmatics are especially prone to problems. The drain flies can carry diseases, and once inhaled into already sensitive lungs, they can cause even more problems. If you suspect a drain fly problem and are living with an asthmatic household, it would be wise to take extra precautions and medication until the problem is eradicated.

Drain Fly Control

At present the best control you can have over drain flies is prevention prevention prevention! If you do not supply a place for the drain flies to get food and reproduce then they will not survive. There are a few simple steps and day-to-day ideas that can seriously decrease your chances of getting drain flies whether for the first time or the sixth.

Drain and pipes are the largest offenders in the case of drain flies; it is not unusual for them to have standing or left over water in them after use. It is important to flush the drains on a regular basis in order to stop insects living in them. If you haven’t used a pipe for a long period of time, flushing the drain may only get ride of the larvae and pupae, but constant flushing should slowly get rid of the adults. Although there are chemicals that you can use to assist with the flushing, it is up to you to keep up the habit or new ‘colonies’ will begin to form.

These are some other important factors in your home to keep an eye on and clean regularly.

  • Run your garbage disposal at least twice a day with hot water running. If you do not have a garbage disposal, make sure you are still flushing the drain with very hot, soapy water daily.
  • Clean indoor plant trays. If left even for a few days, this shallow water can become home to the drain fly.
  • If you rely on a septic tank keep in mind that this is a huge offender. Have it checked and cleaned regularly, but even more important make sure that there are no leaks that could create a shallow pool of water.
  • Check air conditioners to ensure no standing pool is accumulating under the unit.
  • Redirect any water away from the house; ensure that rain gutters have a clear downward path away from your home.