Many times animals will do this when they have a deprivation from weaning. The suckling need is in all young animals0-- humans included. When you factor in that ferrets are not usually fully weaned until 8 weeks of age ( sometimes longer) and they arrive in a pet store at 5 1/2 weeks of age-- that is pretty clear that the ferret is still requiring to suckle, nurse from it's mother. This is one explanation I can offer, and feel comfortable saying with my first ferrets did observe. How to curb it-- well , you won't if ferrets are sold that young. The only other times I have observed this is in older male ferrets who were diagnosed as adrenal symptomatic-- go figure? My personal opinions only, Alicia [Posted in FML issue 3015]