Why hasn't a feature film been made about cats?

Quite often, especially when watching films with Russell Crowe in them, I think that I would rather watch a film with my cats as the leading roles. They are highly amusing and one wonders how much one influences one's pets, in much the same way as one wonders how much one's parents has influenced one. Today we had a bit of a drama. Marmite had brought in a blackbird chick which Trotsky then pounced on and Phil eventually saved in a tupperware sandwich box, releasing it to the relative freedom of next door's sycamore, which it apparently flew into with ease, so another happy ending. The yanks would love it.