Yes, they have to eat a lot to prepare for the winter hibernation time. In most of the books/homepages you will read that the hibernation time lasts from November-March. Well, this is not the case in the northern Sweden where we live. Hedgehogs are hibernating from late September, beginning of October until May! This is a long time for them. The temperatures are often down to -20C for weeks....it is good if lots of snow will come to give them extra protection by isolation (soft powdery snow is great!). Hedgehogs are living in Sweden at leats as far north as in Luleå, latitude 65°. This is really a challenge and such an incredible example of the adaptation to the environment.