In the original London production, the rats were mechanical and remained stationary through the scenes in which they appeared, though squeaking sound effects were used. Tinker took away Carl's detached body parts instead. Peter Zadek wanted to train real rats for the German premiere (Sarah sent him a note wishing him good luck with the task!) but I don't know how he got on... When a friend of mine directed a production, she reluctantly decided in the end to leave out the rats altogether.
Archive 31-12-2003