Are these tiny flies coming out of my bathroom drains drain flies?

Are these tiny flies coming out of my bathroom drains drain flies?

Yes the tiny flies in your bathroom are drain flies

Last week Lynette, who is one of our Service Partner clients, sent me a photo of her bathroom floor enquiring whether I knew if these tiny flies seemingly coming out of her bathroom drains were drain flies. My simple reply was yes as they are more prolific in spring and summer when temperatures exceed 20°C.

The photo above is dramatically magnified to illustrate the number of drain flies in a small area.

Lynette was concerned that no matter how many times she sprayed the flies to kill them, there was always more flies the next day. In fact, what disturbed Lynette the most was that they just appeared to multiply and accumulate on the walls and floor but only in the one bathroom. The flies were nowhere else in her home or in the other bathrooms.

Cleaning your bathroom won’t eliminate drain flies

Lynette was exasperated and frustrated that no matter how often she cleaned her bathroom, the drain flies just kept returning and multiplying.

She repeated to me what I’ve heard multiple times over the years, that she would clean the bathroom with a powerful supermarket bleach cleaner and by the next day the drain flies would have returned.

A friend had told her to buy a 2.5-litre container of bleach and pour it into all her drains in the bathroom which would kill the flies within 24 hours. After using all 2.5 litres of bleach the drain flies were still there.

What are drain flies?

Drain flies are more annoying than anything else as the sheer numbers in your bathroom are unsightly creating, an illusion that the bathroom is not clean.

They do not bite nor do they transmit any diseases of any sort. Nor do they damage clothes, towels or linen. 

Drain flies are prolific breeders which is why people like Lynette get frustrated as the more she appeared to kill, the more prolific they became.

The flies themselves are only around 3-4mm in length being dark grey in colour with hairy moth-like wings which as you can see in the photo below dominate their body size.

Why do drain flies only appear in bathrooms?

If you don’t live on an acreage block with a septic tank or sewer treatment plant, then the only place you will probably experience drain flies is in a bathroom. In septic tanks of sewer treatment plants drain flies breed prolifically but don’t stray far from the tanks which are their food source.

In bathrooms, the flies during the day appear to do nothing other than just sit on walls or under the vanity basin or on the ceiling. This is because they are more active at night, which is why you will seldom see them flying or actually emerging from you floor waste drain.

Even though they are poor fliers the flies are frequently transported by the wind away from septic tanks or sewer treatment plants for distances of 3-5km. This can allow them to enter your home through your insect screens as they are small enough to get through the holes in the mesh. Ultimately they will search for your bathroom floor waste drains because this is where they can feed and breed.

Where do drain flies live and breed?

Since drain flies are such poor fliers, they will always be found within a few meters of the bathroom floor waste drain. This is why you only ever appear to see them in a bathroom.

Infestations occur once temperatures exceed 20°C in spring. The rationale that they keep multiplying is not misplaced as their life cycle is 1-3 weeks from eggs hatching to becoming adult flies. They are prolific breeders with eggs hatching within 48 hours to become larvae. The larvae then mature within 12 days feeding on the decaying organic matter in the bathroom floor waste drain. The adult flies emerge from the drain at night that you then see on your bathroom walls and ceilings will live no longer than 2 weeks.

How you can eliminate a drain fly infestation in your bathroom?

Controlling and eliminating adult drain flies and larvae is by eliminating breeding sites in your bathroom drains. The pouring of bleach into the floor waste trap will typically work if you have a minor infestation.

A major infestation will not be solved by bleach as you need to thoroughly clean the and seal the floor waste trap to eliminate their food source and breeding ground.

From experience, we have found cleaning the whole area around the floor waste and inside the drain with Aquatemp Surface Sanitiser & Disinfectant will clean and disinfect the drain flies breeding ground and food source. 

If you are experiencing the annoyance of drain flies that will not go away give us a call at Whywait Plumbing on (07) 5580 4311 to book a service call so we can eliminate them once and for all.

Aquatemp Surface Sanitiser & Disinfectant 1 Litre Spray Bottle $36.92

Aquatemp Surface Sanitiser & Disinfectant comes in a ready to use spray bottle that eliminates the drain flies food source and breeding ground effectively plus sanitises, disinfects and protects for up to 24 hours.

Why Are Drain Flies Coming Out Of Bathroom Drains?

Why Are Drain Flies Coming Out Of Bathroom Drains?

Recently here at Whywait Plumbing, we have had several calls from clients who are concerned they are about to be overrun by small drain flies in their bathroom. Generally, the concern is that they are in large numbers, and no matter what is done to kill them they continue to multiply as there is always more the next day.

Cleaning Your Drains Doesn’t Get Rid Of Drain Flies!

Many clients had cleaned the bathroom until it could be cleaned no more. So by process of elimination, they had decided that they were coming out of one of the drains in the bathroom. Frustratingly no matter how often some clients sat and observed the drains they never saw any of the drain flies emerging from the drain in the shower or basin or the floor waste. Many clients describe them as lazy flies as they just accumulate on the bathroom walls and seldom fly.

What most people observed was the drain flies flying were mainly sitting on the walls or ceiling in the bathroom. We can confirm that what everyone was experiencing is what is commonly known as drain flies or bathroom flies emerging from the floor waste drain where they breed.

What Do Drain Flies Look Like

what do drain flies look like before being eliminated by Whywait Plumbing Services

A typical looking drain fly on a bathroom wall

Drain flies are dark grey flies and are 2mm – 4mm in length with hairy moth-like wings. They have a jerky flight as they are weak fliers and usually are found close to the floor waste drain or other areas of origin such as shower or bath wastes. This is why they seldom stray outside the bathroom. In most cases, they are breeding in the bathroom floor waste trap.

Drain flies do not bite and are not known to transmit disease of any sort. They do not damage clothes or linen and are considered to be more of unsightly nuisance value in your home.

The adult drain flies and larvae can be controlled by eliminating or reducing breeding sites. If the infestation is minor, the pouring of bleach into the floor trap will usually work in killing them. However, if that does not solve the problem, then you will need to kill them by thoroughly cleaning the drain lines and or sealing of the floor trap.

The reason that they continually seem to be in large numbers despite always killing them is that eggs hatch in 32 to 48 hours when the temperature is above 20 degrees. The larvae mature in 9 to12 days and feed on the decaying organic matter that accumulates in the floor waste trap. The life cycle of drain flies is 1-3 weeks. Adults drain flies live about two weeks, with old ones dying and new ones emerging. They feed on the wastewater in the floor waste trap. During the day the adults rest in shaded areas such as under the basin or on walls near plumbing fixtures and the sides of showers and baths. Most activity occurs during the evening when the flies are seen hovering about.

Septic Tanks Breeders

If you are on acreage and have septic tanks or treatment plant, they may breed in large numbers in and around the tanks. Drain flies then may be carried by prevailing wind to nearby homes up to 3 kilometres away. Adult drain flies are small enough to pass through ordinary window insect mesh screens.

Thorough Cleaning of Drain and Traps

It is the experience of Whywait Plumbing that cleaning of the drains from the basin, shower and bath that discharge into the floor trap is only part of the answer. It is also beneficial to clean the floor waste trap and grate thoroughly. We recommend cleaning the whole area with No-Rinse Floor Cleaner, Sanitiser & Disinfectant, which will clean and disinfect the floor and drain.  We don’t recommend the need to continually pour chemical such as bleach down the drain as it is washed away as soon as you use any water in the basin or shower fixtures.

Drain Pro eliminates drain flies installed by Whywait Plumbing ServicesDrain PRO™ – The Drain Fly Solution

In 2010 Gary and Michele Mays the owners of Whywait Plumbing Services went through this entire experience of drain flies invading their ensuite bathroom. Gary Mays installed a Drain PRO™ unit into the floor waste which prevents not only drain flies but also bacteria, odours and insects from exiting through the drain into the bathroom.

It is three years since the installation of the  Drain PRO™ units in all of all bathroom floor traps in their home, and they have eliminated the reoccurrence of the annoying tiny lazy drain flies.

If you are experiencing the annoyance of drain flies that will not go away give us a call at Whywait Plumbing on (07) 5580 4311 to book a service call so we can eliminate them once and for all.

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