The drain fly goes by many names including filter fly, sewer fly, drain fly and drain moth. It is a teeny little bug that is commonly seen around drainpipe openings. It measures no longer that 1/5 of an inch, so it can be very hard to spot at times. It has hairy, dark wings that make it resemble a miniature moth. Fortunately, drain flies do not bite. Unfortunately, they multiply like crazy, fly out of drains and hang out on a walls and ceilings. It is not a good flier, so if you notice drain flies in a room, you will most likely find its breeding source in that room.
You are most likely to experience an infestation of drain flies after you have been away from your home for awhile like on a vacation. These pests are often found in stagnant water. So once the drains in your home have running water flowing through them again, you can eliminate any young drain flies. Adult drain flies can escape the wrath of the drain, though. They can survive at cold and hot temperatures, so turning your water on at different temperatures will not eliminate adult drain flies from your drain.
Places that drain flies can be readily found are in moist manure, drain traps, septic tanks, garbage cans, dung, storm drains, damp leaves, inside toilet bowls that are not regularly used, in any type of drain in a garage or basement, and anywhere else that has stagnant water.
Larvae of drain flies are found in bird feeders, moss, thick mulch, or under plants or air conditioners. They feed on decaying animals and plants they find outside; indoors, they eat decaying food in drains. So if you do not clean your drain out regularly, you are practically inviting these pests in as roommates. When you see those black like worm-like larvae you know you've got a drain fly infestation.
Immature drain flies are extremely hard to identify because of their tiny size.
However, you can try a simple trick to determine if drain flies are camping out in your home. Take a small plastic cup and spread a layer of petroleum jelly or vegetable oil on it. Set the cup very close to a drainpipe. Wait a couple of days and check the cup. Look closely for any larvae. They are gray with dark bands across their backs. This technique will help you not only find where the drain flies are living, but it will also help you catch them because they will get stuck in the sticky film.
Another way to find out if you have drain flies is to set some fly tape over the opening in your sink, sticky side down. Wait about 24 hours. If you see tiny flies on the tape, you know you have just been paid a visit by drain flies.
If you have drain flies breeding under the floor slab you may have to open the slab and have all the contaminated soil removed. These flies live in the algae and mold that grows in wet environments. Do not try to spray more liquid pesticides into cracks in the slab. It will only make matters worse. The moisture problem must be located and fixed. Call a plumber, not an exterminator.
Comments
John
23 Feb 2009, 15:37
Hi
my problem is a little bit different. I have a small fitness salon and for
the last two, three months, worms have been coming out of the shower
drains. They have been coming out of all them and once out, they start
moving up the tile which of course is very disgusting. The worms look like
mini garden worms and are about 3 to 5 cm in lenth.
Any idea how to get rid of this problem? The pipe system is probably about
10 meters long.
Ask the Exterminator
23 Feb 2009, 16:11
The shower drains go into the floor a foot or two, then take a turn that
looks like an upside-down "P". That shape is meant to hold water at the
bottom of the pipe to prevent sewer gases from coming back up the pipe and
escaping into your salon. If there was no water you would smell the sewer
gas immediately. It stinks!
The fly larvae are not living under water. That means they are living on
the sides of the pipe before it gets to the water. Conclusion: Open the
floor drain cover. Take a round toilet brush and dunk it in some liquid
dish detergent like Joy, and scrub out the pipe down to the standing water
below. Then, rinse with cold water and your problem is solved.
Karen
25 Feb 2009, 23:30
I have these small moth like flies from my bathroom drain, and have noticed
the number is fast increasing...we are getting more and more every day. If
I were to scrub the drain would this definitely stop them from breeding in
the drain or do I need insectisides as well?
Please help.
Ask the Exterminator
26 Feb 2009, 12:52
You don't need any pesticides or bleach. Just open the drain cover and
scrub down to where you see the water at the bottom of the pipe. Rinse with
cold water and the breeding flies are history.
doug
04 Mar 2009, 22:37
i have small black worms wich i know are larvae in 1 of my toilets......how
do i get rid of them
Ask the Exterminator
05 Mar 2009, 06:34
The larvae cannot breed under water, so they must be breeding in scum
buildup under the lip of the toilet rim.
Sounds like you've got a cleaning job ahead. Use a mirror to inspect the
rim and clean it with a toilet brush and any toilet bowl cleaner.
vinita Handlon
03 Apr 2009, 17:23
We have been noticing flies around our guest bathroom windows for about a
week. My husband refused to believe me when I told me they were coming from
the toilet. It so happened that our toilet was giving us some problem (
taking two flushes) so we decided to remove the toilet. Lo and behold the
small flies started to fly out of the 4 inch drain at the base where the
toilet meets the floor. My question is how were these flies coming through
the toilet? Do they swim?. Could they have come through the vent or may be
a frog died and they are on that. How do we treat them? Should we wait till
they are all gone before we put the toilet back. Incidentally there were no
leaks at the base of the toilet either. The drain looks very clean. Since
this is the guest bathroom and we do not use it very often, sometimes not
for days, could this be the problem. Please help me with any suggestions as
it is driving us simply crazy. We can seem to sit in any room at nite
without them flying around us!! GROSS!! We do not have them in any other
room at all. Thanks for your help.
Ask the Exterminator
03 Apr 2009, 17:28
It's only a guess, but those flies only appear to be coming directly from
the drain. They are most likely coming from the seal around the pipe. You
need to keep digging, so to speak, until you find the moisture source and
the decaying matter that these flies are feeding upon. You might have to
hire a plumber to check the problem with a drainline camera to pinpoint the
problem.
Drain flies in the office
22 Apr 2009, 12:20
Hello my question is this for some time now we have been dealing with drain
flies in my office.Im a Doctor we have had the pest control people in and
they do fine work but the problem continues to persist.In your opinion is
there something that I can do to rid the office of the situation.I dont
know if I can use something to clean the Ac/Heating pipes without the need
for a very costly plumer.Is there any over the counter product that I can
use to help rid the place of this problem for good.I know this is an
unusual question but any info that you can provide will be most
welcome.Thankyou..
Ask the Exterminator
22 Apr 2009, 17:06
Take two asprin and call me in the morning. I've always wanted to say that
to a doctor. Sorry! Persistent drain fly problems are usually caused by a
plumbing leak. The constant moist environment is a natural breeding spot
for flies that feed off mold and algae. If your office is built on a slab,
the leak could be below the slab and the drain flies are finding their way
out via tiny cracks in the floor tile grout.
If this sounds like your problem you need a plumber, not a pest control
pro. The tainted soil would have to be dug out and replaced. Big job!
Leslie
29 May 2009, 00:01
Hey Exterminator Man and the folks out there:
Just like to report there is light at the end of the tunnel!
We did get a soil remediation/restoration company to remove the sewage
contaminated soil under our house. They disinfected with enzymes, dried
the area with fans. We are now drain fly-free, for now at least, and
hopefully, for good!
PS-- these compananies are not cheap! It oost us $1,500. But if this
problem happens to you, go with the more $$ company if they do the job
right, FIRST TIME.
Pierre
16 Jun 2009, 17:52
Hi, Thank You for all your input. I read everything here a week ago and
poured liquid plumber gel down every drain and washed with hot water.
Cleaned the bathroom and especially the toilet really well. Cleaned the cat
litter box lid as it had scum build up like the toilet rim. Flies are now
history.
Tracy
19 Jun 2009, 00:20
I have just moved into an apartment that I have a 3 month lease on for a
summer internship. I am pretty sure that I have drain moths. I cleaned
the toilet bowl and tank, bathroom sink, shower drain, kitchen sink as
directed. They are gone from those areas. Now I think they are coming
from the fridge. Is that possible? How do I fix that? The landlord is my
boss and not responsive to my request to getting rid of these himself.
Should I just put up with them for the next 2 1/2 months?
Ask the Exterminator
19 Jun 2009, 07:27
As you can see from the many comments on this page, drain moths can
originate from any one of a number of sources. It's the landlord's
responsibility to fix the problem. Your landlord is also your boss. Bad
combo! Put up with them.
Alex
28 Jun 2009, 17:48
I posted here on April 13th trying to find the breeding source of drain
flies. I finally hired a sewer company, they camera'd the line, and sure
enough there was a deteriorated pipe beneath my kitchen sink. Waste water
from the kitchen sink and dishwasher has been emptying out from the pipe
under my cement slab floor.
We have excavated from the outside and tunneled under the home to replace
the damaged pipe. Still trying to completely remove all moist soil.
'insane from the flies' if you are seeing that many, you need to have a
company camera your sewer line for a cracked pipe.
Observer963
19 Jul 2009, 16:35
I am glad I found this site. We had discovered these thin blackish worms
about 1/2" long in the toilette bowl in one of our bathrooms about a year
ago after only a few months of installing this new toilette bowl. We first
thought of a human parasite. But they didn't fit any of the descriptions.
Every few months we would see one but we couldn't figure out what they are.
As it so happens we moved that toilette bowl to a different bathroom and we
happened to put bleach under the edge yesterday. Since then whenever we
flush the toiletter about 20 of them are wiggling in the bottom of the bowl
and don't seem to be dying either. I am not sure if they really get flushed
out or not although I don't know how they would resist the water
pressure!!!! Since we actually moved the bowl to a different bathroom and
they are still there, it leaves me to believe that these things in fact
live inside the bowl somewhere!!! Is it possible that they live within the
walls of the porcellan? If so, how would be get rid of them, or can we?!!!
And we definitely don't see as many flies as we have seen larveas so far or
at least we haven't noticed them. Thank you
Ask the Exterminator
20 Jul 2009, 11:41
Water courses through the top rim of the toilet bowl to create a rinsing
action. The larvae you are finding seem to have made their home in that
channel. I would contact the manufacturer for suggestions on how to
thoroughly clean the interior of the toilet. The larvae are most likely
feeding on algae or mold.
Anne
27 Jul 2009, 04:06
There are dark red worms about 1/2cm long coming out of a crack in the
shower recess floor. What are they and are they a health hazard? I have
only just noticed this.
Ask the Exterminator
27 Jul 2009, 08:54
Those are the larvae of some type of filth fly. Obviously, the "filth fly"
tag given to any number of these flies indicates something that you don't
want in your home. You need to pull up the floor, clean out the breeding
flies and replace the floor to prevent further leaks.
Karen
31 Jul 2009, 22:24
Please help me. A few years back I noticed these small black flies around
the house mostly in the bathroom or kitchen. I did some research and have
concluded that they are drain flies. I think?? What I dont understand is
that they have not gone away. I have tried almost everything. I purchased
Bio Clean and used it for 8 days straight and I am still finding them. I
dont have multiple problems. I usually find 3-6 a day here and there. I
only find one at a time never more than that. Bio Clean did not work, will
DF 5000 work?? Please help me! I am so frustrated. If it is not a drain
fly, what is it?? All of my drains are used on a regular basis why is this
still occurring?
stephanie
01 Aug 2009, 13:58
i am so frustrated ,i have drain flies in my master bedroom.i have put
drain killer in all my drains and cleaned everything i can think of.my
house is on a slab.i have read some of the other peoples comments and i
dont know where to turn .it seems like the drain flies are comming out of
no where.we dont have standing water anywhere.we went on vacation and
sealed up the house ,when we returned and put our fans back in the windows
here they come again.our water table is about 3 foot down. the house was
built in the 70's.can you please help me..thank you
Ask the Exterminator
01 Aug 2009, 18:04
Answers for Karen and Stephanie:
Often times these small flies can develop under the floor slab. If there
was a plumbing problem where water was able to sit under the slab and mold
developed, these flies could have established themselves. If the drains
have been totally cleaned with a long handled toilet brush all the way down
to the water level inside the drain and you are still finding flies, it's
time to think about what is happening under the floor tiles or even the
floor slab itself. Call in a plumber.
edward
01 Aug 2009, 21:35
I keep reading that you are supposed to clean the drains with a long
handled brush? It does not seem like my drain coverings can even come off
so that I can clean them with a brush. I do not understand why these drain
killers made to rid the drain flies does not work. Do they come out of
the faucets? I have the tub drain covered with a fully sealed covering and
I can still find them. My house is also built on a slab so I can not see
underneath the house. How will a plumber do that?
Ask the Exterminator
01 Aug 2009, 23:01
If you cannot open the drains you cannot clean the sides of the drains
properly. All drain covers can be removed...one way or another. The flies
do not come out of lthe faucets.
If a problem exists under the slab a contractor would have to open a hole
in the slab and dig out any contaminated soil.
sarah
08 Aug 2009, 19:37
i have brownish larva maggot looking things in my washing machine draw.
where u put the soap powder etc in.
they are all crawling abt which makes me freak out. (i cant stand maggots)
they are in and around the draw. i clean the draw and them out. only they
seem to come back. is there a way i can get rid for good as ive got ocd and
the thought of them over my clothes when washing them.i never leave clothes
in the drum until wash day. i live in a flat so i have no way of getting to
any drains.
can you help with some advice. as ive never had this before. thank you.
Lori
10 Aug 2009, 23:35
Please help!! We just moved into a new master bedroom/bathroom in our house
above the garage. There are a ton of black flies in the bathroom and now
the bedroom. I vacuumed up about 40 tonight in the bathroom and killed 10
buzzing around my head while I am sitting in bed. I am freaking out. Is
it possible for us to have drain flies in a brand new bath that's on the
second floor? I know there's no fruit around. Please help. I am ready to
move!! This is disgusting.
melanie
11 Aug 2009, 09:05
I am pretty sure we have drain flies, after reading everything posted...I
noticed them last week around the tub drain (on the 2nd floor of our house,
and the only tub)and we used Drano, which completely got rid of them for a
couple days. Now, they are back, and we think there may be moisture in the
walls do to failing caulk on the shoer tiles. It is possible that they
could be breeding in there, correct? This is the only place in the house
they show up, and they still congregate around the tub drain. Help!
keith
11 Aug 2009, 10:25
last year i had drain flies-i have an old 1888 house-on camera inspection
there were several problems with the pipes- i had the basement floor ripped
up and all the pipes replaces (this cost $25,000)
This summer some flies have returned - does this mean contaminated soil or
another leak or other- i have put some drain fly eliminator down all drains
and its better but not gone- please advise
Jenny
11 Aug 2009, 12:30
Our house is barely over a year old. Last summer we had drain flies only
in our master bath. We did everything to get rid of them. This summer, we
have drain flies again. Our plumber said they were coming from the bathtub
drain since we were not using the tub enough. We ran hot water, poured
bleach down the drain. We also had the plumber clean the all the drains in
the bathroom professionally. Now a week and half later, we have still have
D drain flies but now we have a new problem. We have small, black bugs (a
few look reddish) crawling on the floor, on the bath wall, by the window.
They seem to hang around the tub area. I can't seem to get rid of them. I
have noticed lots of dead drain flies and these little black bugs by the
window where I sprayed Raid. Could the window and not the tub be the
source of the problem? What could these little black bugs be? They are
about 1mm, wingless, don't fly or jump. I need to know who could help us.
We have an exterminator coming today but please advise.
Larry Jones
24 Aug 2009, 15:15
We have been fighting drain flies in our master bathroom for three weeks.
Our county agent identified them for us & suggested we clean all the drains
with bleach. We tried the bleach treatment for a week & the flies might
have slowed but not much. They are attracted to light & we can usually vac.
10-15 off the ceiling. Our house is 2 years old not on a slab. I have
crawled under the house looking for a plumbing leak and don't see one. I
have checked the gutters to make sure they aren't clogged. In desperation
we covered all the drains & overflows with tape & they still appear on the
ceiling. they usually appear close to recessed lights over the tub.
Beth
24 Aug 2009, 16:25
We have lived in our house for a year and a half and only during the summer
months do we really notice an influx of these drain flies. We have a
basement and within one of the rooms is a door to a crawl space (with a
dirt floor) where a sewage pump is housed. The room with the crawl space
access is the room with the most drain flies. Who should we call to
eliminate this problem?
Emily
25 Aug 2009, 01:17
We returned from a 10 day vacation and found about 20+ black worms in our
toilet on the second level in the house. None in the first floor toilet and
one dead one upstairs in the 3rd floor toilet. It sounds like larvae.
What do you suggest? Do I need to clean more than just the toilets? Thanks!
gina
29 Aug 2009, 18:07
Hello so glad to have discovered the name of the flies in my basement. We
have a brand new home, with a finished basement (no carpeting just polished
stained concrete) I just had the bathroom hooked up 4 months ago, in May
(installed shower and toilet) I was just in the basement (August) and
couldn't believe the fly infestation!! The spiders are real happy!!
I can't figure out where these all came from? The bathroom has only been
used about 4 times. We also have a sump pump pit in the back part of the
basement. Could they be in the sump pump? If so how could I possibly keep
this clean?
Also we have very dense clay soil, I know there was a plastic layer put
under the slab, and the side walls are water proofed.
thanks so much for your advice, wanting to know if the builder is
responsible for any of this??
matt
30 Aug 2009, 01:02
Hi. We have been noticing drain flies in our house. It is not confined to 1
area though. They are all over the house. There are many of them in the
upstairs bedrooms, in the laundry room in the basement. I have seen them
just about everywhere else as well. I do not know where they are coming
frome and i have not noticed any larvae. Do you have any suggestions for
me? Thank you.
Gina
30 Aug 2009, 12:50
Hi a follow-up to my post.
I was in my basement today and I discovered there were definitely flies
coming out of the lift pump for the downstairs toilet/drains. I'm not sure
how sealed this pit is supposed to be but I will ask my plumbers to come
back and seal it up. I suspect the bathroom drains were dried out allowing
flies to travel from lift pit to the bathroom. So gross, but now I know
what I have to do.
thanks for this board to hep me make some conclusions. ; )
Jeff
01 Sep 2009, 07:38
Hi, i found this discussion board while trying to figure out what exactly
the black flies are that have taken over my basement bedroom.We have only
lived in the house a year and we didnt have this problem until now.We were
told when we moved in that our kitchen sink(which is right above the
basement bedroom)wasnt properly vented.when water goes down the drain it
gurgles.And i have noticed black mold on the wall vent in the basement
bedroom which i have been trying to get rid of.I have used several methods
to rid the mold but i noticed when it rains it returns.Could this be the
breeding ground for these drain flies?Also the corner of the room where the
drywall was connected it seems to be loose.U push on the wall and it goes
in a little.With all that said, am i going to have to rip out the drywall
and have a plumber check the drain pipe from the sink as this could be the
problem area?I know this is a lengthy post but im at my witts end with
these annoying things.Thanks, Jeff Ky
Sarah
09 Sep 2009, 21:03
We have tons of these coming out of all the drains in the apartment we
recently moved too, along with a sewage smell. The landlord sent their
plumber over today and he poured Drano down the pipes (which we'd already
done) and seemed to be resistant to doing anything else. Any suggestions
for how I can get them to take action? There's literally swarms of the
flies in the bathtub, rendering it unusable - we've had to throw out our
loofahs and soaps and everything because they were covered in flies. We
just began our lease here and I don't think I can handle driving to a
friend's every day to shower for the next year!!!
Allison
11 Sep 2009, 16:23
I've recently discovered drain fly larvae in my shower stall. My house is
brand new construction, less than 6 months old. My shower is not tiled, it
has a fiberglass surround. I was cleaning the shower (with a bleach based
cleaner) when the larvae first appeared. My problem is that the larvae do
not seem to be coming from the drain, they seem to be coming from under the
calking where the shower door frame meets the fiberglass surround. The
problem is still new as I haven't seen many flies, just a lot of the black
larvae. What can I do to get rid of these since pouring anything down or
cleaning out my drain seemingly won't solve the issue. Thanks!
Cherie
26 Sep 2009, 10:59
I manage a bar and the flies are horrible around the beer tappers and the
drain epecially in the morning any suggestions.
Ask the Exterminator
28 Sep 2009, 10:19
Please post questions at top of page.
Caroline
13 Oct 2009, 22:32
I have these wonderful drain flies in my upstairs master shower stall
(fiberglass one piece). They appear to possibly be coming from the seal
around the inside of the shower wall/shower door. It does have mildew in
it, but the rest of the shower is clean. I spray it with bleach often, but
it still continues to have mildew and larvae. Can that be torn off and
replaced to get rid of the problem?
Any advice you could give I would really appreciate! Thanks, Caroline