This was first recommended to us by an FHL member, Gail. We find that one of our ferrets doesn't like it alone so we tend to mix it with a pelleted litter. This stuff is INCREDIBLE for odor control and marvelously clean, plus if you live in an area where mold sets up in just hours at times (which happens here in certain seasons) you will be very happy to know that using enough of this litter in the mix has eliminated the mold allergy problem Steve would at times get from litter. (We still have to closely watch things like the toilet tanks, windows, etc., of course. Oh, a tip about black molds -- we learned on a site devoted to them that the most dangerous ones do not like plain old soap which is why the black molds which can start in in showers tend to be not as much of a problem, so we run a streak of soap along the edges of window panes and it has really reduced to frequency of the growth.) Here is the manufacturer's site: http://www.huntclubinc.com/html/default.asp Here is the deodorizer used in it: http://mineral.galleries.com/minerals/silicate/clinopti/clinopti.htm Which begins: >THE MINERAL CLINOPTILOLITE > Chemistry: (Na, K, Ca)2 - 3Al3(Al, Si)2Si13O36-12H2O, Hydrated > Sodium Potassium Calcium Aluminum Silicate > Class: Silicates > Subclass: Tectosilicates > Group: Zeolites > Zeolite Family: Heulandite > Uses: As a chemical filter, chemical absorber, water purifier and as > mineral specimens. > Specimens and continues: > Clinoptilolite is used in many applications such as a chemical sieve, > a gas absorber, a feed additive, a food additive, an odor control agent > and as a water filter for municipal and residential drinking water and > aquariums. Clinoptilolite is well suited for these applications due to > its large amount of pore space, high resistance to extreme temperatures > and chemically neutral basic structure... See those sites and elsewhere for more info. We buy it through Agway and get a LOT for a bit less than the price of the an equivalent weight of processed wood pellet litters, but the volume is much, much larger so a bag lasts much longer. We have tried a LOT of things over the years and are extremely pleased with this litter for mold control, odor control, lack of mess, and cost. I gather that there is a kraft (i.e. cardboard pieces) version which is larger for use in stalls (and may be what folks have recently been discussing but I have been too busy to more than skim those posts) which is even cheaper but must be purchased in larger volumes. [Posted in FML issue 4846]