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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, every drain fly seems to multiply as there is always more the next day.

Cleaning Your Drains Doesn’t Get Rid Of A Drain Fly

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, accumulating on the bathroom walls and seldom flying.

Most people observed that the flying drain flies were mainly sitting on the walls or ceiling in the bathroom. We can confirm that everyone was experiencing 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 and 2mm – 4mm long 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 the shower or bath waste. 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 diseases of any sort. They do not damage clothes or linen and are considered to be more of an 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, pouring bleach into the floor trap will usually kill 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 the floor trap.

They continually seem to be in large numbers despite always killing them because 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 under the basin or on walls near plumbing fixtures and 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 plants, they may breed in large numbers in and around the tanks. Drain flies 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 Drains and Traps

It is the experience of Whywait Plumbing that cleaning 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 NoRinse Floor Cleaner, Sanitiser & Disinfectant, which will clean and disinfect the floor and drain.  We don’t recommend the need to continually pour chemicals 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 the 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, call Whywait Plumbing at (07) 5580 4311 to book a service call so we can eliminate them once and for all.