Chana,
 
I have a playpen, called a Korral, from Kritter Koncepts in Wisconsin,
the supporting half of The Ferret Nook.  They come in three sizes, made
by hand of wood frame and Plexiglas.  High enough that no ferret that I
know of can get over.  At times it's a little awkward to reach in, but
there is a Dutch door on one side to get in.  Pricy?  Yes, but worth it.
They fold up on hinges to be flat.  Shippable by Greyhound bus.  I keep
four ferts in it and hang cubes from lumber I secured over the top.  One
side has litter pans, and I cover it at night with a black cloth which
rests on the crossbars.  I can fold it up and take it along to picnics,
etc.
 
Check it out.  www.kritterkoncepts.com   You'll have to click on the
"What's new" arrow to get to the next page.
 
Carol O.
[Posted in FML issue 4289]