They start running away when they feel your presence, although they do not react to changes in lighting.
When you try to squeeze them, they start hopping.
They are tiny (as seen on the toilet paper image) and seem nearly translucent, hard to notice.
Every room is filled with them. Eastern Europe.
These are booklice [книжная вошь, книгоед] (Psocidea: Liposcelidae); basically harmless nuisance pests that feed primarily on mold spores, etc., but sometimes can damage starchy materials. Reducing indoor humidity levels as much as practical will help keep their numbers down.
Thank you! This seems to be the insect.
