Guess the dominant animal

In this youtube. (THis is a great video of a cat and two rats).

http://www.metacafe.com/watch/2235731/rat_loves_cat/

What is the rat doing at the end to the cat? He/she is grooming the cat, by which I mean attempting to remove the cat's whiskers. In rodents, the dominant rodent will remove the whiskers of all subservients. I wonder if the cat will realize it could just eat the rat!