(You tell age by dental eruption.) Even this method is unreliable if the mother was fed incorrectly when carrying or feeding the kits, mothers having a very large litter can have problems feeding which can cause retarded kit development. I think this is probably the main cause of small underdeveloped 8 week old kits that appear for sale from time to time. Chris The Wessex Ferret Club www.ferrets-r-us.co.uk [Posted in FML issue 3792]