In New Zealand, weasels are considered pests because of their threat to native wildlife.
In Switzerland, they've proven to be a threat to one of the most advanced experimental science facilities in the world.
The wily predator caused a "severe electrical perturbation" when it bit through a wire at the European Organization for Nuclear Research's (CERN) large hadron collider in Geneva.
The facility's £3.74 billion machine is famous for its experiments in trying to find the "God particle", or the Higgs Boson.
The animal died from electrocution, but succeeded in shutting down the machine for a few days.
A report from the CERN said: "Cause: short circuit caused by fouine on 66kV transformer."
CERN spokesperson Arnaud Marsollier said there were few remains left of the "fouine" (French for weasel).
The large hadron collider (LHC) is a 27km circuit which runs under the Swiss-French border.
The facility sends protons around its tunnel almost at the speed of light. The energy released when the protons collide is used to create new particles.
CERN's report said it was "nor the best week for LHC!"
The LHC was shut down in 2009 when a bird reportedly dropped part of a baguette on a compensating capacitor.