Snake Puzzle Challenges Readers to Engineer Length-Specific Escape Routes

The puzzle asks readers to design two escape passages, A and B, for snakes of equal width but different lengths in a cage. Passages may have no moving parts, trapdoors or levers. Snakes have cross-sections of diameter and cannot squeeze through narrower openings. Passage A must let short snake exit; passage B must let long snake exit.

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The solution uses a looped tube for Passage A that exceeds the short snake’s length but is shorter than the long snake’s, creating a block. When long snake reaches the loop’s junction, its body blocks movement, preventing escape; short snake passes unhindered. Passage B uses a floor opening short snake cannot cross; long snake’s rigidity lets it pass safely.

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The riddle first appeared in Kvantik Magazine in 2014 as a brain-teaser. In April 2026 the puzzle was republished on The Guardian’s science page, continuing a tradition of Monday challenges that blend mathematics, geometry, and thinking. The column’s format invites readers to submit solutions and new puzzles.

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Snakes share the tube’s diameter. The Guardian publishes challenge; Kvantik Magazine supplied the 2014 source. Readers of the column form audience invited to solve and extend the puzzle.

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Snakes share the tube’s diameter. Passage A’s loop exceeds short snake’s length but is shorter than long snake’s, creating a block. Passage B uses a floor opening short snake cannot cross; long snake’s rigidity lets it pass.

The GuardianThe Guardian

The puzzle illustrates how spatial reasoning and geometric constraints can be applied to everyday-like scenarios, encouraging readers to think beyond conventional solutions. By blending mathematics with a playful narrative, it promotes critical thinking and engages a broad audience, reinforcing the role of puzzles in informal science education and community interaction.

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The puzzle author notes that the official answer to the riddle is “adder.” He also states he will publish the full solution at 5 pm UK on the same day and encourages readers to email new puzzle ideas for future columns.

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No dissenting viewpoints were recorded in the source material.

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• “When the long snake doubles back and reaches the place where the tube meets itself, it cannot get through because its body is blocking the way.” — Puzzle author

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• “The short snake does not have that problem and can pass.” — Puzzle author

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• “I’ll be back at 5pm UK with solutions.” — Puzzle author

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The author will post the complete solution later today and continues to solicit reader-submitted puzzles for upcoming columns.

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