Macbeth says, "The worm that's fled Hath
nature that in time will venom breed, No teeth for the present." What does that mean?
Macbeth says this after he finds out that Fleance has escaped. Fleance will be a problem in the
future, since he will have children who will become kings, but for now Macbeth can let him go and deal with other things because Fleance is of no immediate threat to him personally.