Monna,
 
You were asking about large cages a couple of days back.  Last week, I did
some exhaustive shopping for cages.  The largest I found was at a PetLand
store.  It must have been 5' tall, 3'deep and 5'wide with 3 very large
levels.  It could have held 6 ferrets easily.  They wanted over $200!  I
didn't recall who made it.
 
Seeing this and many other cages (most of which I thought were too flimsy),
I made the decision to try making my own, and have come to the conclusion
its the best way to go.  As I posted earlier this week, metal shelving makes
a great frame for a cage (they type that's made out of sheet metal, is
usually painted grey or green, and the shelves are held in place with bolts
to the corner supports/legs).  These shelves usually come in various sizes.
You could get a set that is 18" deep and 4 feet long and set up shelves
every 16" and come up with a multi floor cage big enough for the biggest
busyness of ferrets.  Just cut openings in the shelves/floors for the ramps,
add a bunch of hardware cloth and wire, drill a few holes in shelf edges to
bind the hardware cloth, and some patient grinding of sharp edges and you'll
have the best cage you've ever seen.  It can be as tall as you want by
adjusting the number and overlap of the corner supports/legs and have as
many floors as you want with the number of shelves.  I have found that
intermediate floors can also be easily made of hardware cloth wired into the
outside walls.  It's a little more time consuming, but handy if you are
short on shelves (as I was when I got my set at a garage sale).
 
The success of the cage is best exemplified by Gus, my carpet shark.  here
is no way he can escape when we are gone for the day, I know he is safe
inside a sturdy cage, plus he seems to love it.  After all, he treats it
like a two story condo (bathroom and dining room on the first floor with
bedroom and playroom on the second).
 
Someday soon I am going to write down some detailed instructions with
diagrams on how to do this.  When I do, I'll put out a notice on the FML.
[Posted in FML issue 1783]