Thanks everyone, Think I'd still like to try her, but as Shona says its Toro and anything edible is fair game to her, infact doesn't even need to be edible lol, I agree too that it would be the chase kill it thing which she does so eliquently with any squeaky toy, she is so fast I don't think the rat would get a bite in but that would depend on her instinct face to face with roland I suppose...
I saw that martin clune series, loved watchin the wee ones killing the rats...