What does the phrase "The worm has turned" mean?

The worm turns comes from an old proverb, "Tread on a worm and it will turn," meaning that even the most defenseless creature will, when sufficiently provoked, attempt to defend itself.

Shakespeare used it in Henry VI, where he wrote, "The smallest worm will turn, being trodden on / And doves will peck in safeguard of their brood."

Even a worm will turn is an expression used to convey the message that even the meekest or most docile of creatures will retaliate or get revenge if pushed too far. The phrase was first recorded in a 1546 collection of proverbs by John Heywood, in the form "Treade a worme on the tayle, and it must turne agayne." It was used in William Shakespeare's play Henry VI, Part 3.

https://en.m.wikipedia.org/wiki/Even_a_worm_will_turn

Most commonly, it is a phrase used when someone who has always been weak and obedient starts to behave more confidently or take control of a situation.

http://idioms.thefreedictionary.com/The+worm+has+turned

A couple of references:

It's one of many derived forms of an old proverb, the base of which is either tread on a worm and it will turn or even a worm will turn. It means 'even the most humble will strike back if abused enough'.

The proverb is first recorded in John Heywood's 1546 collection of proverbs in the form: "Tread a woorme on the tayle and it must turne agayne." Shakespeare uses it, of course: "The smallest worm will turn, being trodden on" (Henry VI, part III). It has remained common in all sorts of literature: "He's a very meek type. Still, the worm will turn, or so they say." (Agatha Christie, The Mirror Crack'd).

http://www.randomhouse.com/wotd/index.pperl?date=19970717

But while the lowly worm definitely gets no respect, even the lowliest critter has its limits, which brings us to the saying that's been puzzling you all these years.

It comes from a very old proverb, "Tread on a worm and it will turn," meaning that even the humblest creature (or person) will resent being badly treated and eventually revolt. The first written form of this adage yet found comes from 1546, and Shakespeare invoked it in his 1593 Henry VI, part II: "The smallest Worme will turne, being troden on." The poet Robert Browning gave the sentiment a bit more pathos in his dramatic monologue "Mr. Sludge the 'Medium'" in 1864: "Tread on a worm, it turns, sir! If I turn, Your fault!"

Just what a worm can hope to accomplish by turning on its tormentor is a bit unclear, but in this case it really is the thought that counts. Extended to human beings, "the worm will turn" speaks of the indomitable human resistance to tyranny...

http://www.word-detective.com/032305.html


Worms of the world, turn!

"Well the worm has definitely turned for you man."

http://www.youtube.com/watch?v=7_8WY3q9BP4