Catchin' flies
Alex, who recently turned three, sat upon the changing table after being awake for a few minutes. His mouth hung open as he struggled to wake up. (Not one of his more intelligent looks.) Don commented to him, "You'd better close your mouth, or flies will get in."
Alex: What? (Said with some surprise.)
Don: Flies are going to get in your mouth. You need to close it.
Alex: (After a pause.) But there aren't any flies in here.
Sarah: There are, too!
Alex: (Suspiciously) Mom, are there flies in here?
Me: Not right now. Probably you wouldn't get any flies in your mouth, but you could.
Alex thought for a moment then said to Don, somewhat triumphantly:
"You open your mouth when you talk!"
Not bad thinking for a three year old! I think Don tried to convince him that while he did open his mouth to talk, he closed it quickly again so flies couldn't get in, but I think Alex realized he had won the argument.