my computer I print up a little label with my ferrets' name, telephone
number, and address.  I then tape this "label" to the collar.  Voila!
Inexpensive collar with ID tag.  If you don't have a printer, try using one
of those labels used for price tags at garage sales (easily found in the
office/school supply section at your local Walmart or Kmart).  You could
even sew bells on the collar too.
 
I have never heard of any ferret fatalities/near-fatalities from collars.
In my experience, my babies can't get their collars off normally, but on an
odd occasion when they get hung on something, they have always been able to
get out of them.  Maybe it's the fact that when they are stuck they pull a
lot harder.
 
Angela
[Posted in FML issue 1441]