Emily, Where did you get Isis? pet shop? breeder? or rescue as a stray? Isis is still fairly young, and should not have been in contact with the newborn kittens. Young ferrets especially, hear the cries of other animals, and it's instinctive for them to go after the source. I even had the experience of a young female ferret getting agitated when it heard a visiting friend's human baby cry. The ferret, normally well behaved, and didn't nip/bite at all, had to be restrained from going after the source of the crying. The ferret was tense and I'm sure would have bitten the baby. If there are other kittens still, I'd definitely separate them from the ferret. Close the room off at least, or keep the ferret in its kennel when unsupervised. If you don't have time to work with this ferret, then check with a local ferret rescue group so they can place it for you. Most ferrets that didn't have enough handling and human contact early on, will be bad nippers, but in this case, perhaps, it's a matter of the kitten's cry and/or smell that set off the ferret to attack. Phyllis [Posted in FML issue 4944]