The Diaper-Wearing Ferret Who Cleaned Fermilab’s Accelerator

Quick Take

• A whole village erased itself from the map to make Fermilab possible, and that's not even the strangest part of this story. Meet the founding team →
• The animal chosen to inspect miles of inch-wide steel tubing was picked precisely because of one instinct it was born with. Why a ferret was chosen →
• Felicia's heroic run through the accelerator solved one mystery but accidentally revealed that the real problem was something entirely different. Felicia's run and its aftermath →

Sometimes, solutions to multi-million-dollar questions require nothing more than a well-placed ferret. There are many stories about the creation of Fermilab, the Midwest’s particle accelerator. However, none are as cute and crafty as the tale of Felicia the ferret. This little mammal might just be the unsung hero of Fermilab.

An irresistible force paradox is defined as an unstoppable force meeting an immovable object. And Felicia the ferret, an animal hired by the U.S. government to dig downward through subterranean tunnels, might be exactly that. Meet this truly special ferret and learn about her unexpected role in the history of particle physics.

The Brain Drain

The story of the National Accelerator Laboratory, which became Fermilab, started when the village board of Weston, Illinois, literally voted itself out of existence in 1966 to provide space for the proposed project. Several years later, it was founded as the National Accelerator Laboratory and renamed in honor of Enrico Fermi.

People working at the lab in the late sixties liked to call it the brain drain, since running such a project called for many qualified workers. This prompted the American government to field employees from Europe. One such émigré was a construction manager named Roy Billinge. To build the main particle accelerator on time, he enlisted the help of a fellow Englishman, Bob Sheldon. Sheldon worked as a fixer, securing every part needed as soon as possible.

Felicia the Ferret

Thanks to the tireless work of individuals like Bob, they finished construction on the accelerator right on schedule. When they tried to turn it on, however, it failed. Something was preventing the particles from circulating through its miles-long stainless-steel tube, no larger than the diameter of a tennis ball. Desperate to get things going but lacking any way to search through miles of inch-wide tube, they turned to the project’s fixer for a solution.

A consummate Yorkshireman, Sheldon quickly suggested ferrets. Small, lanky, and adorable creatures from the Mustelidae family, ferrets love running down tunnels to flush out game. Not long after, Felicia the ferret arrived in a cage.

Quick Work

To make sure Felicia didn’t leave any additional obstructions in the accelerator, the workers fitted her with a diaper and placed her inside the steel tube. A few hours later, she emerged. Though tired, and perhaps annoyed at the lack of discoveries, she was otherwise healthy. Felicia’s brave voyage showed workers that the accelerator had no obstruction.

Later, mathematicians traced the lack of particle circulation to instability in the particle orbit. Once the problem was solved, the workers at Fermilab found a new use for Felicia: project mascot. In the annals of particle physics, not many stories are as cute as Felicia’s. She may also be the only animal to survive travel inside a particle accelerator.