Just wanted to share my experiences with ferrets and other animals:
 
I have 2 ferrets, whom I adopted about a month ago.  I also have a rabbit,
almost 1yr old, who is neurologically impaired (please excuse spelling if
it's wrong).  She had a parasite when she was still in the pet store (not
uncommon for rabbits), but it got into her brain and did a bit of damage.
Basically, all that means is that she's really skittish, and freaks out
easily.  The ferrets have, on occasion, gotten near her cage, and she does
get upset, but if you throw a towel over her cage, she calms right down
(there's that "Out of sight, out of mind" philosophy).  I don't know if
that's true for "normal" rabbits, but it's worth a try.
 
I also have 2 parakeets, and the ferrets have never bothered them at all.
Then again, they don't fly all over the room, either.
[Posted in FML issue 1446]