I got this poem from a great little book called Poetry for Cats by Henry Beard:
There Is No Cat-toy Like a Mouse
by Emily Dickinson’s Cat
There is no Cat-toy like a Mouse
To please me in my Play
No any Yarn-ball like a Bug
That strains to fly away—
No rubber Bauble can delight
No lifeless String divert—
For where is Fun if none feels Fright
Or Joy if nothing’s hurt?