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Coming out of the sewer

Drain flies in the home? You should address the infestation immediately

Fruit fly
Phorid flies are a type of scuttle fly. If there is an infestation in the home, you should act quickly. Photo: iStock / Backiris

October 28, 2024, 3:48 pm | Read time: 3 minutes

It sounds like a horror story: Winged insects that enter the home through the sewer system. We are talking about the drain fly. Although this fly does not bite, it can still transmit diseases. In this article, myHOMEBOOK explains how to recognize an infestation and successfully combat the insects.

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Drain flies may appear harmless due to their small size, inconspicuous brown color, and the fine, fur-like setae covering their bodies. But appearances are deceptive. The fly’s habitat is the sewer system. This is where it picks up pathogens. If you discover drain flies in your home, it’s important to act quickly and implement control measures.

How do you recognize the abortion fly?

The drain fly (Psychoda grisescens) is a member of the moth fly family (Psychodidae), which includes approximately 110 species in Germany. According to the Federal Environment Agency, the small brown fly is around 1.5 to 2.5 millimeters long. This small size makes drain flies difficult for humans to spot. It has fine hairs and regular white dots on the edge of its wings. There are also two black dots on the wings. The larvae are also relatively tiny and are only around four millimeters long.

How dangerous are they for humans?

Although moth flies, commonly referred to as drain flies, do not typically bite, they pose a problem for humans beyond just hygiene concerns. Under certain circumstances, pests can transmit diseases and germs, such as when they come into contact with food. If this food is subsequently consumed, the pathogens are transmitted to humans. Additionally, drain flies can breed in large numbers within a home, leading to significant hygiene issues.

Where do drain flies come from?

As the insects are very small, tiny openings are enough for them to enter homes. They prefer to live in polluted bodies of water such as sewers, cesspools, or sewage treatment plants. If there is a blocked drain in the home, they are also attracted to it. But butterfly flies can also be found in the wild, where they live on the forest floor and feed on fungi, excrement, or animal carcasses, among other things.

Since drain flies are not strong fliers, they often use the wind to aid their movement. However, if it is attracted by dirty water, excrement, or urine, it can fly to its destination. Nearby, the females lay their eggs in the water, where the larvae hatch and feed on putrid, organic material.

Note: The arum, a toxic indigenous plant, emits a scent that is also attractive to drain flies. Here, too, it lays its eggs, and the larvae then grow in the flowers.

How can you control drain flies in the home?

Generally, insecticides are not necessary to manage moth flies, also known as drain flies. Contacting a professional pest controller is also only necessary in extreme cases. There is a simple trick to get rid of the pests: simply vacuum them up with a vacuum cleaner. This method is as simple as it is effective.

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Preventive measures

Naturally, the best strategy is to prevent attracting the diminutive drain flies into your home from the outset. This can also prevent the laying of eggs and the development of larvae. For this reason, drainpipes and traps should be kept clean and cleaned regularly. Open drains and containers with dirty water should generally be avoided in the home.

This article is a machine translation of the original German version of MYHOMEBOOK and has been reviewed for accuracy and quality by a native speaker. For feedback, please contact us at info@petbook.de.

Topics Pests
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