Why are mice not a problem in double-walled structures?

Hello,
we are at the very beginning of our construction planning and are currently reading a lot. One question, for which I have not yet found any information, is the following: Why are mice not a problem with a double-skin wall construction (with 2-6 cm of air) (at least it's not discussed anywhere)? Is it assumed that the skins will be completely sealed for the next fifty years? Or is it not a problem for the insulation between the skins if a large family moves in there?
Karl

If you have enough cats, there will generally be fewer problems with mice. However, this also varies from year to year and depends on the location of the house.

But basically, there are always recurring problems with animal pest infestations in the cavity wall insulation. A mouse needs less than 5mm to slip through. Usually, the cavity insulation cannot be sealed that tightly. And since they also like the cozy warmth of the mineral wool, there can be problems here depending on the population size.

Once the mice are inside the insulation, it becomes very difficult to remove them again.

Search the internet for mice in prefabricated houses, there are plenty of results. And then search for ants in prefabricated houses.

Thank you very much for the quick responses, and with the keyword "Fugenlüftung" I have now also found quite a bit. Obviously indeed (also in new buildings with a double-shell wall structure) a problem. The solution apparently are joint grids (and of course otherwise airtight masonry). Thanks again very much. Karl

double-shell wall construction (with 2-6cm air)

Why an air gap? If you, for whatever reason, install an air gap, there are very small ventilation slots that can additionally be made animal-proof.

Is it assumed that the shells will be completely airtight for the next fifty years?

As airtight as the masonry. So yes.

No air gap = no openings whatsoever = absolutely no pests inside

: after your (presumably rhetorically intended question) I of course googled and found an article by Helmut Künzel: "Zweischaliges Mauerwerk: mit oder ohne Belüftung" (Fraunhofer IBP). His conclusion is: "A fully insulated intermediate layer is unproblematic and allows optimal thermal insulation with the given construction dimensions." Karl