Every worm has his weak spot

Bilbo Baggins recalls his father's saying, 'Every worm has his weak spot,' as a proverbial expression of the belief that even the most formidable adversary possesses a hidden vulnerability, a principle he applies directly to the dragon Smaug during their confrontation beneath the Lonely Mountain.

Origin and Context

The saying is attributed by Bilbo to his father, though it is never quoted directly in the narrative. Bilbo invokes it at a critical moment during the quest to reclaim the dwarves' treasure from Smaug. After the dwarves have been trapped inside the mountain by the dragon's fury, and their spirits are low, Bilbo offers to creep down into the dragon's lair once more. He says, "'Every worm has his weak spot,' as my father used to say, though I am sure it was not from personal experience." The remark is made to the dwarves as a justification for his plan to spy on Smaug, and it reveals Bilbo's growing confidence in his own resourcefulness and his belief that careful observation can uncover a decisive advantage.

Application to Smaug

Bilbo's proverb proves to be more than a comforting platitude; it becomes the tactical foundation for the entire enterprise against the dragon. During his second, more extended conversation with Smaug, Bilbo deliberately flatters the dragon's vanity, praising his "waistcoat of fine diamonds." Smaug, absurdly pleased, rolls over to display his jewel-encrusted belly, and Bilbo sees what he had glimpsed on his first visit: "a large patch in the hollow of his left breast as bare as a snail out of its shell." This discovery of the dragon's weak spot is the direct result of Bilbo's application of the principle that every worm has his weak spot. The information is later conveyed by the old thrush to Bard the Bowman, who uses it to slay Smaug with a single black arrow, piercing the exact bare patch on the dragon's left breast.

Thematic Significance

The saying encapsulates a central theme of the adventure: that courage and cleverness, not brute strength, are the keys to overcoming seemingly insuperable obstacles. Bilbo, a small and unassuming hobbit, is the one who identifies the dragon's vulnerability, not the mighty warriors or the proud dwarves. The proverb also reflects Bilbo's own character development. He begins the story as a comfort-loving hobbit who shuns adventure, but by the time he invokes his father's saying, he has become a resourceful and daring figure, willing to risk his life to test the principle. The saying thus marks a turning point in Bilbo's transformation from a reluctant participant into a decisive agent of the quest's success. It also underscores the narrative's broader moral that even the most powerful and terrifying beings, like Smaug, are not invulnerable, and that a combination of luck, observation, and courage can bring about their downfall.