The city is taking the fight against the undefeated urban rat to where they live and breed. 

The budget approved this week includes $2.9 million to wipe out -- citywide -- so-called rat reservoirs where the vermin congregrate and breed.

"Rats are one New York City institution that we're happy to get rid of," Mayor Bill de Blasio said.  

A first-year pilot program in seven neighborhoods where intense baiting followed the identification of rat reservoirs led to an 80 to 90 percent drop in rat sightings, the city said. 

The expanded program will include the hiritng of 50 new staff members, including exterminators, public health sanitarians and a population biologist. 

amNewYork followed along with the city's top rat expert on a tour of one of the pilot neighborhoods back in September, learning how the city's Health Department was identifying rat burrows and other signs of rodent activity. 

The city says it surveyed 62 blocks under the pilot program, identifying numerous signs of rats.