A large, folding Midwest cage with two shelves came with our first pair
of shelter ferrets... We added an extra floor and some ramps.  Not long
after that, we found an identical cage (minus interior 'shelves') at a
yard sale for $5.  Since the cages are built out of jointed wire panels,
all I had to do to join them was remove one side wall off cage 'A' and
the top half of the side wall of cage 'B' and tie them together with
some plastic zip ties.  (I also altered the 'matched' ends of the plastic
bottom trays by cutting off the outside ridge so they'd fit together more
closely)
 
My boyfriend's son correctly pointed out that since the cage was twice
as big now, we needed to get two more ferrets.  I can't argue with logic
like that, so over the next couple months, that's what we did. ;-)
 
I put in a shelf all the way across the rear half of both cages (in
two sections for ease of installation), and added some extra shelves,
denim-pant-leg ramps, hammocks and other necessities, and for the final
step I cut out a section of the 1/2 height dividing wire panel at the
bottom, and stuffed a heavy-gauge corrugated plastic tube through it,
so our little girl with the lame leg didn't have to climb the ramps to
get from one side to the other unless she wanted to.
 
Miraculously, as long as none of them have an upset tummy, they
religiously use a single litterbox for the whole cage... it's a clear
acrylic "custom commode" from craftycreatures.com, sized to fit the exact
depth of the Midwest cages.  Spendy, but worth the $$ IMO, just because I
don't have to worry about the corner *next* to the litterbox becoming a
second potty... there is no corner next to the litterbox.  :-)
 
--
:: Teresa ::
http://www.mivox.com/
 
"Tact is the ability to describe others as they see themselves."
        -- Abraham Lincoln
[Posted in FML issue 4139]