Drypta dentata (ROSSI, 1790) is a Palearctic species expanding its range across Nothern Europe. 52 new localities of the species, situated in 11 geographical regions in Poland of the species are given and its northward spread is discussed. Currently the northern border of the species occurrence runs in a cental part of Masovia (Warszawa-Wilanów), and the northern border of the highest population density is marked by the valley of the Pilica River. The direction of migration towards the north along the Vistula river valley is noticeable. D. dentata for the first time was recorded from the Masovian Lowland, Upper Silesia, the Lublin Upland and the Bieszczady Mountains. New data on biology of D. dentata is presented. Contrary to some authors, it was observed as being active in the daytime in a large amount of specimens. This indicates that it is not a nocturnal species as previously stated. Authors suggest that insolation is of less importance than soil moisture in the species habitat.