In the years since we have been providing more true darkness we have NOT seen a decrease in benign adrenal growths -- which still have to come out, of course -- (though what we consider "early" for those growths is later than what a lot of others consider "early" so perhaps it's caused a difference in on-set age with a bit of delay *if* it's not a statistical quirk). What we HAVE seen change -- and this may ONLY be a statistical quirk but might be real -- is that we have not encountered ANY adrenal MALIGNANCIES since we began providing such amenities. The single best things we seem to have are some black curtains for the ferret room that I made from doubled sheets, and non-shedding (expensive but, boy, do they last so not expensive long-term) black polar fleece blankets for cage covers and for floor bedding in romp regions. We also have under the platform bed set up for sleeping, and have dark-providing bedding in cages and elsewhere. Watch out for fake fleece of the type that looks like sheep fur and for fake fur; it's not a major hazard, but for some it poses a risk factor. For most ferrets it is going to be safe enough, but some types of those materials shed like the blue blazes and that stuff does NOT pass when it's ingested. If a ferret takes in a lot of it grooming or eating in bed then a blockage can occur. Over the 19 and 1/2 years (as of December) that we've had ferrets we have had only TWO with blockages, One has a stomach problem that might be a disease and might be partly due to him being an individuals with multiple deformities. (Still trying to find a solution after 7 or 8 months, many tests, multiple ultrasounds, multiple biopsies, two surgeries, many meds, etc., and he has an appointment for a new med again on Wednesday when he'll go in with a girl we've got who needs Lupron because she has a reduced and benign R adrenal growth that has invaded her Vena Cava but does not have enough collateral circulation to allow ligation of the vein.) The other boy had a blockage that was thought to be a fur ball till it was tested and then it was found that it was fake fleece and fake fur fibers for the most part. We DO have items with such fabrics since they provide marvelous cushions, but we COVER it with sheet material. This has not happened to any of our others so it likely is normal not a large risk factor, but we aren't alone in having such fibers found in a ferret stomach, and we know that we've got one sweet boy who does that, so it's worth the extra work for us to protect Jumpstart. If you go to http://groups.yahoo.com/group/Ferret-Health-list you will find multiple articles about natural melatonin production. I suggest seeing the recent links to a Science News article on the topic. (Hey, Bill, remember back in 1996 when this darkness consideration first got mentioned? It's like ADV; that was mentioned within the first months or first years of the FML, and like Waartensburg (sp) which also was mentioned long ago... Folks, there is a LOT of accumulated info in the FML archives, so don't forget to look! [Posted in FML issue 3601]