How to Get the Hedgehog Out of the Cage
How to Get the Hedgehog Out of the Cage
It rattles. It spins. The spikes poke out through the bars and it feels loose, almost free, like the next shake will do it.
It will not do it. People have been shaking this one since the 1940s.
Watch: The Solution, Step by Step
The puzzle in the video is a wooden and metal edition rather than ours, but it is the same puzzle and the same solution. If you would rather work it out yourself, stop after the next section.
Nobody Can Agree Who Invented It
Ask a Czech and this is a Czech puzzle. It is Jezek v kleci, the hedgehog in the cage, and more or less everyone there knows it by name.
That fame comes from one book. In 1940 the writer Jaroslav Foglar published Zahada hlavolamu - The Mystery of the Puzzle - the first of his hugely popular stories about a boys' club called the Rychle sipy, the Rapid Arrows. The plot is a hunt for a mysterious object, and the object is this puzzle. Readers went looking for real ones. A factory at Roudnice nad Labem began producing them in 1941 and has been at it ever since.
Except it is not Czech. It was patented in Philadelphia on 7 April 1896 by an American named Clarence A. Worrall, and puzzles on the same principle were already being made in Brooklyn by the Trilby company from 1886.
Except it may not be American either. A Japanese puzzle called Snake and Star - a snake coiled so that it traps a star inside it - appears in a games catalogue dated 25 May 1895, a year before the patent. Different object, identical idea: find the one position and angle at which the trapped thing can leave.
So the national puzzle of Czech childhood is probably Japanese, was patented by an American, and became famous through a novel. Nobody owns it, which feels about right for a puzzle whose whole subject is something refusing to come out.
What You Are Actually Holding
The hedgehog is a small ball with spikes sticking out in every direction. The cage is a barrel with openings cut around it.
First, the thing everyone checks: there is no trick. The hedgehog is solid and so is the cage. No spike pushes in, nothing unscrews, no part is hinged. You are not hunting for a hidden mechanism, because there is not one.
What there is instead is asymmetry, and it is easy to miss on an object that never stops moving. One spike is longer than all the others. One opening is larger than all the others. Those two facts are the entire puzzle.
Why It Fights Back
Most puzzles resist you by refusing to move. This one does the opposite, which is a far better trap.
The hedgehog turns freely inside the barrel the whole time. Every shake produces movement, every movement produces a new arrangement of spikes, and your hands report steady progress to a brain that is getting none. Ten minutes go like that, then twenty. The feedback is real and completely meaningless, because randomly reorienting a body with this many protrusions lands on the one alignment that works essentially never.
It also looks like a fidget toy, so people treat it as one. Nothing here rewards fiddling and force helps even less - if you are pulling hard enough to worry about the spikes, the orientation is wrong and pulling harder will not fix it.
How to Get the Hedgehog Out
Put it down and look at it. All of the work is observation.
1. Find the largest opening. Go around the cage and compare. Most of the openings are the same size, and one is slightly bigger. That one is the door, and it is the only way the hedgehog leaves.
2. Find the long spike. There is only one. It is the reason the hedgehog cannot simply drop out of anything, and it is the piece with the fewest options, so it dictates everything else.
3. Bring the long spike out through the large opening. This is the move. Not the body, not a handful of spikes - the single long spike, through the single large opening.
4. Rotate the hedgehog around itself. With the long spike committed, turn the ball steadily rather than pulling on it. Each rotation walks more of it into the opening.
5. It comes free. After a few rotations the hedgehog is out. Putting it back is the same sequence reversed, which is worth doing once while it is fresh, because a hedgehog left out of its cage is just a spiky ball.
Approached that way it is a two-minute puzzle. Jerry Loo, who has solved several versions of it, reported getting through one in under two minutes and still rated it worth owning. The hour people lose is spent entirely before they start looking.
Frequently Asked Questions
What is the Hedgehog in a Cage puzzle?
A spiked ball trapped inside a slotted barrel. The goal is to get the ball out without tools and without breaking anything. The spikes are different lengths and the openings in the cage are different sizes, so there is one particular alignment in which the hedgehog can leave and a great many in which it cannot.
Where does the Hedgehog in a Cage come from?
Three answers, all partly true. It was patented in Philadelphia in 1896 by Clarence A. Worrall, which makes it American. A Japanese puzzle called Snake and Star, working on exactly the same principle, was catalogued a year earlier, which suggests it is not. And it became a household object in Czechoslovakia after Jaroslav Foglar built his 1940 novel Zahada hlavolamu around a hunt for one, which is why most of the world meets it as Jezek v kleci, a Czech puzzle.
How do you solve the Hedgehog in a Cage?
Find the one opening that is larger than the rest, find the one spike that is longer than the rest, and bring that spike out through that opening. Then rotate the hedgehog around itself rather than pulling, and after a few turns it comes free. It is an alignment problem, not a dexterity one.
Is the Hedgehog in a Cage hard?
Medium, and unusually dependent on approach. Someone who sits down and studies it can be through in a few minutes. Someone who treats it as a fidget toy can genuinely lose an hour, which is why it has such a reputation for being harder than it looks.
Do you need tools to open the Hedgehog in a Cage?
No, and there is no hidden mechanism either - the hedgehog is solid and so is the cage, so nothing pushes in, unscrews or unhinges. If you are applying enough pressure to be concerned about the spikes, the orientation is wrong and more force will not fix it.
Is the Hedgehog in a Cage good for children?
It works well for older children and teenagers, because the goal needs no explanation at all - the thing is obviously stuck and obviously should not be. It also survives being handled constantly, which is not true of every puzzle. Younger children tend to shake it happily without ever moving toward a solution.
Where to Go Next
The Hedgehog in a Cage is the rare puzzle that works as an object even before anybody solves it, which is why it lives permanently on a desk rather than in a drawer. It sits with the rest of the pick-up-and-fiddle range in our desk toys collection.
If what you enjoyed was the realisation that the answer was a single alignment rather than a sequence of moves, the Three-Piece Block works the same way with three pieces and no cage at all.
Everything else lives in the mechanical puzzles collection.