Hi Ophelia, I did some research with input from a Biologist, when I noticed all of mine were getting less active as the days started getting progressively shorter. It turns out that ferrets and other members of the Mustiladae family do indeed become less active as the days get shorter, so winter sluggishness is the norm not the exception. Note, I do not falsely extend the daylight hours by having indoor lighting on at night. I keep night lights on to an absolute minimum and also make sure noise levels are low so not to disturb my fuzzies' diurnal/circadian natural rhythms. I take seriously the studies finding evidence that artificially extending their normal diurnal patterns pre-disposes them to major illness, e.g., insulinoma, adrenal disease etc. And yes I am aware that some breeders do this to bring the jills into season. I am not sure what falsely extending the daylight hours would do to their activity levels other than induce their breeding cycle. It may be that people who keep all kinds of lights on at night do not notice any difference in their fuzzies activity levels. And thank you for the suggested strategy for travelling with a ferret. I'll keep that one in mind! Tressie Tressie A. Dutchyn, MA ID PhD student, Dalhousie University Research Associate Atlantic Interdisciplinary Research Network for Social & Behavioral Issues in Hepatitis C & HIV/AIDS Department of Community Health & Epidemiology Dalhousie University, Faculty of Medicine [Posted in FML 5805]