Felicia The Diaper-Wearing Ferret Was Sent Into A Particle Accelerator For Science


Rachael Funnell

Digital Content Producer

clockJul 5 2021, 11:09 UTC
Felicia The Diaper Wearing Ferret Was Once Hired To Clean A Particle Accelerator

Ferrets are famously good at noodling their way down narrow passages. Images courtesy of the Fermi National Accelerator Laboratory

In the late 1960s, when Batavia, Illinois’, Fermilab was still known as the National Accelerator Laboratory (NAL), the completion of a particle accelerator hung in the balance. While the miles-long stainless steel tube was successfully pieced together on schedule, and within the $250,000,000 budget, its operators soon ran into trouble: the damn thing wouldn’t start.

Inside the ring-shaped, 200-billion-electron-volt proton synchrotron particle accelerator was a gap around the size of a tennis ball from which air was pumped out to ensure the particles being flung through it didn’t meet any obstacles. The team were flummoxed as to what the source of the holdup was and being inconveniently human-sized meant they couldn’t simply go in and look. Enter: Bob.


Bob Sheldon, a worker at a laboratory near Oxford, UK, who was famous for his entrepreneurial skills was hired by a manager at the NAL to be something of a miracle worker. If something went awry or materials were too expensive, it was Bob’s job to find the solution. Sure enough, when the team turned to him in their penultimate moment of need, he had an idea.

Hailing from Yorkshire, where hunting was commonplace, Bob was familiar with the use of ferrets as a means of flushing out rabbits by sending them noodling into burrows. A ferret would fit nicely into a tennis-ball-size hole and would have no qualms following a man-made burrow into the unknown.

felicia the ferret

Fastening a string to Miss Ferret's special collar are (L to R) Don Richied and Wally Pelczarski. Images courtesy of the Fermi National Accelerator Laboratory

While the organic solution was considered a green and cheap one (Felicia cost just $35), it did pose its own problems. It’s all well and good sending in a ferret to find the source of the “blockage” but what’s one to do when that same ferret leaves behind a trail of droppings? According to a report on Fermilab’s own website, the idea of using a laxative before sending the ferret in was floated, but in the end, they settled on a more domestic solution: diapers.

felicia the ferret
Felicia was perfectly adapted for crawling through a 4 mile-long tunnel in search of obstacles. Images courtesy of the Fermi National Accelerator Laboratory

All dressed up with only one place to go, the ferret, named Felicia, was a great success. After completing a few trial runs (spurred on by the promise of snacks) she went on her merry way into the 4 mile-long tunnel and came out the other end. Tired, but in good health. Unfortunately, her recon mission failed to turn up any blockages, so it was back to the drawing board or, more specifically, the mathematicians.

felicia the ferret

Walter Pelczarski with Felicia ferret. Images courtesy of the Fermi National Accelerator Laboratory

Some head-scratching eventually led to a hypothesis as to why the particles had failed to circulate. They believed the stability of the orbit had been compromised, causing particles to crash into the tube’s walls before they were able to complete a circuit. Fortunately, Felicia wasn’t needed to fix it and Felicia was allowed to retire as a laboratory pet and mascot.

Particle accelerators have enabled physicists to gain insights into the big questions underpinning our Universe, but this one might never have made it off the ground were it not for a small ferret.

[H/T: Atlas Obscura]

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