Really important (on the serious side) if having a lot of ways for ferrets to get into complete darkness at any time. Not enough darkness (hence not enough melatonin production by the body) may be a contributing factor/cause for adrenal disease in ferrets. (See some great info in http://www.miamiferret.org/fhc and http://fhl.sonic-weasel.org and http://listserv.cuny.edu/archives/ferret-search.html I love the pocket doors, split doors, wipeable flooring up the walls, appliance safety features, storage, mud room suggestions and loads more of the ideas which have been posted. Hey, does anyone know of any stove tops with metal closing tops (to use like a temporary counter) which can be put down ONLY when the burners are all off? That would help with small kitchens and with climbing/jumping ferrets. If I remain needing to sit when cooking we eventually may need to switch some things to lower heights so such safety feature become important. [Posted in FML issue 4878]