To Jeff Johnston, with regards to ferret-proofing.
I have a couple of points to make regarding keeping your ferrets safe and
out of trouble.  Ferret-proofing the surroundings is most important, but
just in case you don't completely succeed here's what else you should do.
Definitely put belled collars on your fuzzies and keep them on.  My two
have worn the kitten-sized belled collars (with stretchy safety elastic in
case they get hung up somewhere) since babyhood (oldest is 3.5) and I
always buy several when I see them and if they slip them and hide them just
put another on until I come across the missing collar.  It's also not a bad
idea to get a small pet tag and attach it to the collar.  That way if your
fuzzie gets out it is instantly recognizable as a pet and the info.  is
there for him/her (hopefully) to be returned.
 
The other thing is to condition your fuzzies to come to you on command.  My
Elie is naturally attracted to a certain squeak toy, and a treat when they
respond, ferretone, ferretvite, peanut butter, raisin, or the like,
consistently given, will usually do the trick.  That way if your ferret
goes missing you can squeak the squeaker and hopefully be rewarded with a
jingle to help you track them down.  I lived in the upstairs apartment of a
duplex once and both Elie and Pixel got into the crawl space at various
times until I was completely successful at blocking them out.  Fortunately
they came to me when I squeaked the squeaker.  Once I had to wait until the
ferret in question woke up, but I got them back nonetheless and was able to
track them by the jingle sound in the wall and open the appropriate access
panel.  Such ferret explorations are not recommended, but I was lucky in
this case and I think that the belled collars and squeaky toy helped.  Best
of luck.
[Posted in FML issue 1280]