von suckgasse » 3. Jan 2013 13:40
There are differences between southern european and northern european ants.
In general, the southern european ants hibernate from November - February (3-4 months) and the northern or central european ants from more or less October - March (5-6 months). Lasius niger definately needs 5-6 months. There are exotic ants from Asia, Australia or America, that don´t need to hibernate but they also have little breaks where they rest and recuperate.