Given the melatonin discussions and increasing evidence of the many useful functions of melatonin in bodies, the ancestral dawn and dusk activity for ferrets, and the ever increasing work on negative health impacts of too much light exposure for a wide range of mammals (including ferrets and humans) I figured that these would be interest: http://www.sciencenews.org/articles/20060318/bob10.asp (This one may not be available to all viewers until next week, but I think it should be available now. It affects most of us more than the parks, but you get the point about degrees.) [Site's down now so can't tell. So I cleared cookies for nothin'. BIG] http://www2.nature.nps.gov/air/lightscapes/ http://www.inquinamentoluminoso.it/worldatlas/pages/fig1.htm (Here is a satellite view of how darkness levels vary at night around the globe. It is very intriguing that not all industrial world populated areas are as bright as others. For instance, although we are in an area which is suburban and near preserves including a national one, the region is close enough to NYC and highly populated enough that it is far brighter than even the cities of Australia which I guess either means that they are much less populated or they are doing something very right in terms of light pollution, or both.) In so much of the human range we have made night no longer night for all species. You can learn more by searching on such terms as: scotobiology and melatonin To see more on various functions of melatonin in bodies: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi One of our ferrets is currently not sleeping in darkness as much as he should, but it is short term. While I have had influenza Hilbert (who is typically trustworthy for not getting himself into harm's way) has been lying down on the floor about 5 feet away from me and guarding me very often during the fevers. Ferrets are so marvelous. Steve and I did it for him when he was ill and now he is doing it for me. -- Sukie (not a vet) Ferret Health List co-moderator http://www.smartgroups.com/groups/ferrethealth FHL Archives fan http://ferrethealth.org/archive/ replacing http://fhl.sonic-weasel.org International Ferret Congress advisor http://www.ferretcongress.org [Posted in FML issue 5190]