I found a couple of other forums that contain these lyrics, and it seems the verse quoted by Guest above is missing a couple of lines:

One morning just at four o'clock,
Somebody tried to pick our lock.
I knew it was Pa, just as sure as sin,
So I opened the door and let him in.
Ma said, "What time is it, Pa?"
"It's twelve o'clock," my pa told Ma.
Just then, the cuckoo cuckooed four
And Pa made me cuckoo eight times more.