Drain Fly


Actual Size: 1.5 to 5 mm

Characteristics: Small; short, hairy bodies and wings, giving them a furry appearance.

Legs: 6

Wings: Yes

Antennae: Yes

Habitat: Live and breed near standing water in drains, septic tanks, composts across New Jersey.


  • May appear suddenly from sinks and bathtub drains.
  • Get their name from the fact that they often breed in drains.
  • Being tiny flies, they can easily crawl through normal fly screens.

Drain Flies in North Jersey

Drain flies, also sometimes called moth flies, are part of the Psychodidae family. Named for their tendency to reproduce in drains, drain flies can be found all over the United States. They can be highly annoying and occasionally shock homeowners when they emerge unexpectedly from sinks and bathtub drains. They can multiply in vast numbers in sewage treatment facilities and subsequently be blown to nearby structures by the wind, where they may pass through fly screens.

Drain Fly Habitat

Drain flies thrive in muck that builds up in areas like sewage lagoons, septic tanks, moist compost, and unclean garbage containers. They breed in drains in sinks or bathtubs, tree holes, rain barrels, moist organic matter, or birds’ nests that have accumulated fecal matter. Damp or stagnant water with slimy film is an ideal breeding ground for the drain fly. Inside buildings, drain flies can often be found on glass windows, doors, lamps, and other sources of indoor lighting.

Drain Fly Behaviors, Threats, or Dangers

Drain flies don’t bite people, but due to their tendency to hang out in unsanitary environments they can spread diseases. Like all flies, they can also easily become a nuisance if trapped in your home. If you have a blocked drain, your risk of drain fly infestation becomes higher. Bathroom drains are the most common type of drain. Drain flies are not strong fliers. They can often be seen crawling on surfaces and walls.

Do you have a drain fly issue on your property? Contact north Jersey’s experienced fly control company.