Because he was a-thinking.
“Pee-wit! pee-wit! Yes, that is it!
Pee-wip! pee-wop! pee-wee!”
Three little birds
Flew down to the ground,
And soon, by working very hard,
A fine fat worm they found.
The third flew down between them,
(The middle one was he,)
And ate it up like winking