Dark-winged fungus gnat - Sciaridae family

Photos are taken in my apartment - my wife bought soil for the flowers and after some time they started to fly around. Small, about 1.5 mm, very annoying insects. I don't think further identification is possible.

The life cycle of only a few species has been studied in any detail, mainly those which are pests of commercially grown mushrooms. Sciarid larvae are mainly found in soil and plant litter, where they seem to feed mainly on fungi and animal faeces. Also, some species mine in plant parts above and below the earth. The larvae play an important role in turning forest leaf litter into soil. Sciarid flies are common pests of mushroom houses and of plants grown in protected culture, for example herbs, where the warm and moist conditions favour their rapid development. In commercial mushroom houses, sciarid fly larvae tunnel into the stalks of the mushrooms, and feeding damage can sever developing mycelium, causing mushrooms to become brown and leathery. Their faeces may also prevent the mycelium from colonising the casing layer, severely reducing yields. As a pest of plants, sciarid larvae feed on the root system. In both industries, adult sciarid flies are a nuisance pest that can result in crop rejection if high numbers are present in the growing area.

The damaging larval stage can be controlled using the beneficial nematode Steinernema feltiae, which enters the larva and releases a bacterium that kills the insect. The nematode then reproduces within the larva and its young are released into the growing medium, where they actively search out new host larvae.
From Wikipedia