Instead of spending tens of millions of dollars on rat control (i.e.: extermination), the city should phase in a program that either supplies every building in the city with metal, sealed disposal units or forces landlords to purchase them by law.
Leaving unprotected bags of trash around in any case should, over time, become a serious violation with fine penalties. Above is a home-made solution to rats. It was devised and built by my landlord, who, by the way is nearly 95 years old. If he can do it, so can you.
In the meantime, contact the mayor or your representative to push for more rat-proof garbage containers around the city.