New construction: Ants coming out from the baseboard?!

Remove the baseboard and take a close look at where they are coming out.

Then get some ant powder at the hardware store. Take some of it, dissolve it in water, and put a little of this solution directly into the hole where the ants are coming out. A few drops of it are enough. I do the same outside between the stones. After that, you won’t see any ants anymore.

Afterwards, you can seal the opening with a little plaster and that’s fine.

And why this is immediately considered a construction defect here I do not understand right away either. Over time, you will find many insects in or on your house. That is just how nature is. It tries to take back what was stolen by humans.

We also find spiders in the house every year, especially when autumn approaches.

We don’t care. We leave them alone and in return they leave us alone.

I am not someone who immediately runs to a lawyer or something like that, but rather prefers to first ask other people about their experiences. I think that's better. Since I don’t know that many people, I find the forum a good idea.

I also always find it useful when the thread starter writes down their own thoughts on the matter.

Personally, I find it strange that 1.5 months after completion there is a small crack in the exterior masonry through which insects come in. Nothing comes in through the windows, so I think it must be in the masonry below ground level. I personally cannot imagine that this is within the tolerance range during construction, because I thought everything had to be airtight by now. But if you say that fine cracks or holes in the masonry through which insects get in are normal for a 2-month-old house, then that fits. If you had said it’s not normal, or if I were convinced that it is a construction defect, I would have gone to a building expert. But as I said: I prefer to ask about experiences first before I open a big can of worms.

By the way, the search for the hole is not that easy: If I search from outside, I have to dig a lot and move aside the black dimpled membrane. From the inside there is a membrane between the screed and the wall, but I can’t look underneath it either because I can’t just lift the screed to look behind the membrane down to the foundation slab.

Place a trap directly at the currently found location and wait to see if anything changes.

I also thought that if there is really a small hole in the masonry or [Sockelbereich] (we don’t have a basement), then moisture will also get into the house. I always thought that window and door areas have a certain tolerance, since it’s “only” about driving rain and such, but masonry and [Sockel] have to be tight.

This is what it looks like behind the baseboard. Is that mold, or building material from the ants, or ...? The house isn't old enough for that to be just dust.

Yep, that is mold...