Bit of a silly question, but I thought this was really funny and now I can't remember what it was in. A main character can read minds, including, I'm pretty sure, animals' minds, and is travelling with a cat, among others.
She (I think it was a she) tries to read the cat's mind, but the cat's thoughts just consist of "mip? mipmip?" in varying levels of impatience. Cats, apparently, don't know themselves what they want - that's your problem.
It sounds like it could well have been Terry Pratchett, but if so I don't know which book it was.
EDIT: My mind is now insisting that it was the Acorna series, or something like it? I did a bit of searching but can't find any reference to this, though she certainly is telepathic and does have a cat in at least one book, I see, and what the descriptions say seems vaguely familiar. Could this be?