About the Data

What is NYC 311 and how are rodent complaints recorded?

NYC 311 is the City of New York's non-emergency service request portal, operating 24/7. Residents report rodent sightings, conditions attracting rodents, and related issues through the 311 phone line, website, or mobile app. Each complaint is logged with a complaint type (Rodent), sub-type descriptor (Rat Sighting, Condition Attracting Rodents, Signs of Rodents, Mouse Sighting), ZIP code, and date. Complaints are published in near real time on NYC Open Data under the CC BY 4.0 license.

What happens after a rodent complaint is filed?

A 311 rodent complaint triggers an inspection by the NYC Department of Health and Mental Hygiene (DOHMH) for residential and commercial properties. Inspectors visit within a defined response window and record results: Passed, Failed for Rat Activity, Failed for Other Reason, Bait Applied, and others. Property owners are legally required under the NYC Health Code to remediate any failure. All inspection results are published in the DOHMH Rodent Inspections dataset (p937-wjvj).

What are NYC Rat Mitigation Zones?

In 2023, NYC DOHMH designated the first Rat Mitigation Zones — neighborhoods identified for concentrated rodent abatement, heightened inspection frequency, and multi-agency coordination. East Harlem (ZIP 10035 — the top-ranked ZIP in this index) was among the first designations. Properties in these zones face more frequent proactive inspections. The NYC Rat Information Portal allows residents to check a property's inspection history.

Is this index affiliated with the City of New York?

No. The City Rat Index is an independent data analysis project. It is not affiliated with, endorsed by, or operated by the City of New York, DOHMH, or any other NYC agency. All data is sourced from publicly available datasets under the CC BY 4.0 license from NYC Open Data.

How often is the data updated?

The underlying NYC Open Data datasets are updated continuously by the City. The figures in this index were last pulled on 2026-06-25. Check the methodology page for the exact queries used.

Where can I find licensed rat exterminators in NYC?

Licensed pest control operators in New York State are registered with the NY Department of Environmental Conservation (DEC). For properties in high-index areas, professional treatment — rather than DIY bait — is generally more effective at breaking the infestation cycle. Residents can find licensed NYC operators through the DEC registry or through verified Google Business Profile listings.