This rat bin was used to collect dead rats from the streets for bacteriological examination in the collective effort to control bubonic plague. There were 650 rat bins, which were attached to lampposts, in different parts of the city and suburbs. Each bin, filled with carbolic acid for disinfection, was visited twice daily by a rat collector to gather the rats for examination. Each rat was marked with the number of the bin to indicate the location from which it was collected. When a rat was found to be plague infected, the area was surveyed carefully for disease.