We must control waste from restaurants of Mumbai. Most of the restrurants in Mumbai throw their waste food in open areas or bins where the food is accessible to rats and stray docs. One solution is to have a separate night-time collection system in the city only for restaurants and hotels. These establishments should be charged separately for the collection and transportation of waste food while the food itself can be useful for making either bio-gas or as a fuel or fertilizer.
Another long term solution is to make ISO14001 (certification for EMS) mandatory for all industrial and commercial establishments in the city
According to my estimates there are AT LEAST TEN million rats in Mumbai.