The Siberian flying squirrel (Pteromys volans) is an Old World flying squirrel ranging from the Baltic Sea in the west, throughout Northern Asia to the coast of the Pacific Ocean in the east. They favour old forests with a mix of conifers and deciduous trees. They are mostly nocturnal, being most active late in the evening, although females with young may also feed during the day. They do not hibernate, but in the winter they may sometimes sleep continuously for several days.
