It costs me never a stab nor squirm
To tread by chance upon a worm.
“Aha, my little dear,” I say,
“Your clan will pay me back some day.”

Dorothy Parker (1893-1967) American writer

“Thoughts for a Sunshiny Morning,” New Yorker (3 Apr 1927)
    (Source)

Reprinted in Sunset Gun (1927).