Louis Antonellis of the International Brotherhood of Electrical Workers, Local 103, was arrested near the Capital Grille, the Boston Globe reported. He was identified by employees at the restaurant as the man who walked in and loosed three white lab rats concealed in a shopping bag.
The union is apparently involved in a dispute with the restaurant, although the Globe said the details are unclear.
"I'm all for the union's right to organize, but that is not a tactic that is going to earn them support anywhere," said Michael Ross, a member of the city council and occasional Capital Grille patron.
A city spokeswoman said the rats are in quarantine at an animal shelter and will be available for adoption once they are determined to be disease-free.