From coffee shops in Hougang to the rubbish bins of Pasir Ris West, rats are a familiar sight. While residents and stall owners have largely learnt to live with the rodents, town councils say that they are stepping up with new campaigns and routines to control the rat population.  Every day for three years, Ms Hannah Kim Santiago’s 6am walk to her polytechnic from her home in Pasir Ris West meant sharing the pavement with furtive, grey "companions". As a university student, she no longer takes