ᐅ Can flies enter the house through the mechanical ventilation system?

Hello everyone,

For some time now, I have noticed tiny flies in the bathroom, about the size of fruit flies. At first, I thought they might have come in from outside through the window during air ventilation and removed the flies.

We were away for a few days and kept the windows closed, but there were still some flies in the bathroom. I remove them, and the next day there are more.

So far, there have been no flies in the other rooms, but yesterday I spotted one in the living area, although it could have escaped from the bathroom.

What do you think, is it possible that they are coming in through the ventilation system?

Thanks

Is it a centralized or decentralized mechanical ventilation system with heat recovery? Actually, both types should have filters installed beforehand.

When we moved in, a few small flies came out of the electrical outlets.

We had some nesting in a flower pot, which then spread throughout the entire house. They also tend to come in more often through fruit.

I find it unlikely that they could enter the house through a central mechanical ventilation system. In this scenario, it seems most probable that they came into the house during ventilation and then built a "nest" somewhere (for example, also in the ventilation ducts).

Sounds like fungus gnats. They are usually brought into the house through potting soil and new plants, and these little pests can be quite persistent. Just place some yellow sticky traps in the flower pots and that should solve the problem. 😉

RotorMotor schrieb:

Is it a centralized or decentralized mechanical ventilation with heat recovery system?

It is a centralized mechanical ventilation with heat recovery system.

WilderSueden schrieb:

Some had settled in a flowerpot and then spread throughout the house. They also often come in with fruit.

We don’t have any plants on the upper floor and only one large one on the ground floor, but the insects are not there. They are found exclusively in the bathroom! There is nothing on or around the fruit or in the kitchen either.

RomeoZwo schrieb:


In this scenario, I consider it most likely that they entered the house during ventilation and then built a "nest" somewhere (for example, also inside the ventilation ducts).

That could be...

I couldn’t clearly tell if they are really coming out of the ventilation duct, but based on your description, it might be possible.

HnghusBY schrieb:

Sounds like fungus gnats. They usually get into the house through potting soil and new plants.

I looked them up, they are not fungus gnats...

I will take a photo later.