No. Nonononononono.
The setup would seem to indicate poison. (And almost everytime we've seen Ferris it's been in the cafeteria.)
Poison's really bad once it gets in rats since they can't vomit it up. (Anthropomorphic rats may vary.) And if his breathing's ceased...
This may be the end of Ferris. Or, even scarier, we may find out what Ferris' near-death experience looks like.
