As any kid will tell you, it's important to have your own "space" ...
My husband made a half-door for our spare -now the ferret- room so that we
could see in but they couldn't get out.  I use a large cage to keep them out
of trouble when no-one's home or we're all asleep, or when I'm vacuuming.
Otherwise, they have run of the room, and it's been f-proofed for them.  I
don't give them run of the whole house; frequently one at a time will get
supervised house exploration and "tickle chase down the hall NO STAY OUT OF
DADDY'S SPEAKERS where'd the cat go can I bounce on the waterbed?" time....
The only furniture in the room, besides the 2 cages, are a closed dresser
(no way to get under or inside it), a file cabinet (ditto) and a sturdy
storage chest, which is just high enough they can get under it to play.
They have their toy basket, the pet taxi, the occasional cardboard cave, a 2
story cat condo, various tubes, tunnels, toys, etc.  to play with on a
rotating schedule, and several litter pans in their chosen spots.  I keep
the cages covered with large towels when they're out to play, since they do
love to climb on them.  This protects them from getting their paws caught in
the mesh when they jump off (Litje pulled a back leg muscle as a kit this
way - got hung up on the way down - so, no more bare-top cages.) They get an
hour out in the am while we get ready for work, and usually 5 - 6 hours
every pm, so they get plenty of exercise.  Of course, having four ferrets
makes it easier on them to amuse themselves when no one is in the room with
them.  The room has been dubbed "Woozlevania."
 
Blessings,
Carla & the Woozlemaniacs
Litje (Waterbed Breakdancer Extraordinaire), Turlough (Where's the Kitchen?),
Gaoth (Wheeeeee!) and Quidni (Look, Mom, I can Fly! oooOOPS!)
[Posted in FML issue 1458]