I've noticed several 'do not want' words, but 'that's vile' is always scratching on something that makes noise, like a handy box or paper, for effect. Simba will do that to let us know where he has had a furball (or to complain if it's not cleaned up to his satisfaction) and to indicate that he doesn't like the current version of food. But he's not shy about *saying* he doesn't like something, either, though it seems to be a combo of letting off steam and informative gossip.
(no subject)