I wrote this one years ago when I was a grad student in experimental psychology at the U. of Illinois. I may have forgotten part of it.
Tune: What Have They Done To The Rain?

What Have They Done To The Rat?

Just a little rat running down the maze,
He's starv-ed and shock-ed until he's in a daze,
Frightened all to pieces to see if he'll drop feces
(or "Scared out of his wits to see how much he defecates") What have they done to the rat?

Just a guilty rat who ate fobidden grain,
He's cowering in fear and shame!
But how could he know better? How could he refrain,
When just the day before, they took out half his brain?
What have they done to the rat?