What kind of creatures are these? And where do they come from?

If you get close, they become active.

<1mm

Then that could fit, they are usually 1 to 1.3 mm in size.

Do they jump?

Found them here with us today as well, on the wall in the laundry room. Hmm, strange

New species ...occurs only in the new building ....

Here's a picture from 2018:
(the critters are actually so small that you can't get a good focus on them with a phone)

[ATTACH alt="IMG_20180720_095355.jpg" type="full"]43249[/ATTACH]

We have had them since then (July 2018) in 2-3 rooms in the wall corners.

You can squash these things all you want - they always come back
But it is also not clear where they come from/reproduce etc.

I suspect they "feed" on moisture/fungi on the felt plaster, since there are no flowers or anything like that where they appear in our place
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At the same time, we sporadically have (every few weeks one) these strange reddish worms:
(But in other rooms and in the middle of the walls)

Quite likely ladybird larvae that live predaciously. They possibly feed on the booklice.

Lifestyle Booklice depend on a habitat with high relative humidity and mainly feed on mold fungi. These insects reproduce throughout the year inside buildings. Their lifespan is about 10 to 12 weeks. Occurrence Booklice live, for example, on the ground under fallen leaves and are also found in many households. They are often found in bathrooms or on windowsills – especially when there are houseplants present. Booklice are distributed worldwide and are especially found in damp basements, new apartments, or libraries. In freshly wallpapered or still damp new apartments, mass proliferation often occurs. The animals feed on the barely visible mold growth on the wallpaper and leave behind a fine paper dust.