hello! I want pet rats. How do I persuade my housemate this is the best idea ever? She doesn't really like any pets (she is a biologist though, just not the animal-enthusiast sort).

They would have to live in the sitting room and she might have to occasionally feed them if I'm on holiday, so 'not telling her' is not an option.

Any ideas welcomed, otherwise I'm just going to tape this picture all over our flat. Aw! http://animal-world.com/encyclo/featured_pets/Critters/Darla/BabyAndMom_.jpg