So, Edward, the way I see it is that you want us to measure the size and weight of the individual pieces of kibble we are feeding our ferrets and then measure the size and weight of the resulting poop. Well, that seems to me that it has a few logistical problems if this is to be a true scientific study. First, it assumes that the ferret is kept alone and that we can identify the little piles left by the individual ferret. Second, it assumes that the ferret ate nothing other than the food that was fed it. We all know that ferrets never stash food or treats for later and they surely would not pick up something we or the dog dropped. Third, it assumes that the age, weight and "port" conditions of the ferrets are all known and that the ferrets' innards are healthy. Otherwise, we will not have the necessary knowns available to find the unknown. So, I think that I will continue to deposit the used food in the compost pile. I may look at it intently, but I doubt very seriously that I will be taking measurements! Please let us know if you find anything interesting. -- Renee Downs "Eventually we will realize that if we destroy the ecosystem we destroy ourselves." Jonas Salk "The most effective way to do it, is to do it." Amelia Earhart It's amazing how much can be accomplished if nobody cares who gets the credit! Ferret Emergency Response, Rescue & Evacuation Team (F.E.R.R.E.T.) http://www.ferretemergency.org [log in to unmask] International Ferret Congress http://www.ferretcongress.org American Red Cross http://www.redcross.org [Posted in FML 6137]