The "food chain" in some animated cartoons is even longer, with one additional step on each end:

apple | worm | bird | cat | dog | dog catcher | spouse

There's one short where a thought balloon appears above the bird's head, with the text . o O Dogs chase cats... cats chase birds... I'm a bird... I gotta help the dog! /msg yerricde if you know the title of this one, which ends with the worm using a pin to push the other characters several feet up in the air and then taking a shower inside an apple.