<http://www.smallanimalchannel.com/ferrets/ferret-interaction/20-fascinating-facts-about-ferrets.aspx> On ferrets having both types (short wavelength and long wavelength) of cones in their eyes, indicating that physiologically there is potential for seeing a wider spectral range than some had thought: http://www.ncbi.nlm.nih.gov/pubmed/12699079 http://www.ncbi.nlm.nih.gov/pubmed/11328346 Types and locations matter. Years ago we had a ferret who would preferentially steal and stash blue items, at times having stash places with only blue things, indicating a reason to question previous thought on this matter for at least some individuals. She taught when she stole... Yes, I know there were people in the U.S. with pet ferrets before the 1970s; that is when they began to be found in more than rare families. When we first had ferrets in our family over thirty years ago pet stores were already selling them but some stores were actually selling unhealthy biting fur fitch to customers rather than healthier pet stock ferrets. Some private breeders back then also had unhealthy and very inbred stock. Back then if a person was not careful it was possible to get ferrets through either approach who had enough genetically wrong with them that some lines would USUALLY die below three years of age. After that early time there wound up being healthier stock usually with standard markings available -- yes, MF, Colorado Ferret (the original farm is long defunct), PV, and certainly Wendy Winstead -- actually increased pet store ferret lifespans which doubled and tripled compared to way too many of the earlier sources. More recently with so many fancies introduced, the lifespans of some lines have decreased once again for other genetic reasons, though it is still quite normal to have ferrets reach middle seven to middle eight years, sometimes older. Although I wrote the linked article at the top, below that article you will find other links including another in the 20 points series that Wolfy wrote: <http://www.smallanimalchannel.com/ferrets/ferret-behavior/20-strange-but-common-ferret-behaviors.aspx> [Posted in FML 8048]