The National Labor Relations Board has upheld unions’ right to display large, inflatable rats at workplaces of secondary employers, including companies that hire nonunion firms to build or retrofit buildings.

In a May 26 decision, NLRB’s three Democrats—Chairman Wilma Liebman and members Craig Becker and Mark Pearce—said the use of rats at such workplaces is not coercive. They said unions protesting at a hospital did not shout, block access or otherwise disrupt hospital operations.

The board’s only Republican, Brian Hayes, dissented. He said, “For pedestrians or occupants of cars passing in the shadow of the rat balloon, which proclaims the presence of a ’rat employer’ and is surrounded by union agents, the message is unmistakably confrontational and coercive.”