An update on Thomas -- Thomas is still ataxic and still growing like a weed. I never thought that ferrets cost that much to feed :). Thomas had an MRI done: they thought that maybe the cerebellum was small, but they weren't sure since they had never done an MRI on a ferret. I've had three of the four microchipped. It was quite an ordeal. Needless to say, the needles used to insert the microchips are rather large (14g or 16g), and the ferts were rather traumatized. They seem to resent vaccinations more now, but other than that they're no worse for the wear. As far as the size of the microchip itself, it really isn't that big. In fact, I can only feel the microchip in one of my ferrets. As far as the information stored on the microchip itself, it is just a number. However, the number is then stored on a big computer somewhere which also has the information of owner name, number, address. The different microchip companies are making scanners that can read other companies microchips. That's about all I know about microchips. If anyone is considering having their fert microchipped, I would recommend having an experienced microchipping person perform the microchipping. Lisa [Posted in FML issue 1997]