Little Billy sat playing in the garden.

When his mother came out to collect him, she saw that he was slowly eating a worm.

She turned pale.  "No, Billy!  Stop!  That's horrible!  You can't eat worms!"

Trying to convince him further she noted, "Now the mother worm is looking all over for her nice baby worm."

"No, she isn't," said Billy.

"How do you know she's not?" said the mother.

"Because I ate her first!" answered Little Billy.