Methodology

What data sources does this report use?

This report uses two publicly available datasets published on NYC Open Data:

1. NYC 311 Service Requests (dataset ID: erm2-nwe9) — all service requests submitted to the City of New York's 311 system from 2010 to the present. We filter this dataset to records where complaint_type = 'Rodent'. Available at: data.cityofnewyork.us/…/erm2-nwe9 .
2. DOHMH Rodent Inspections (dataset ID: p937-wjvj) — rodent inspection records from the NYC Department of Health and Mental Hygiene, including inspection results such as "Passed", "Failed for Rat Activity", "Bait applied", and others. Available at: data.cityofnewyork.us/…/p937-wjvj .

Both datasets are maintained by the City of New York and licensed under the CC BY 4.0 license, which permits reuse with attribution.

How were the API queries constructed?

All figures were retrieved using the public Socrata Open Data API (SODA). The exact queries used:

311 rodent complaints by borough (Jan 2025 – pull date)

GET https://data.cityofnewyork.us/resource/erm2-nwe9.json
  ?$where=complaint_type='Rodent' AND created_date >= '2025-01-01T00:00:00'
  &$select=borough,count(*) as complaint_count
  &$group=borough
  &$limit=10

Top ZIP codes by complaints (Jan 2025 – pull date)

GET https://data.cityofnewyork.us/resource/erm2-nwe9.json
  ?$where=complaint_type='Rodent' AND created_date >= '2025-01-01T00:00:00'
  &$select=incident_zip,borough,count(*) as complaint_count
  &$group=incident_zip,borough
  &$order=complaint_count DESC
  &$limit=20

Monthly complaint counts (Jan 2025 – pull date)

GET https://data.cityofnewyork.us/resource/erm2-nwe9.json
  ?$where=complaint_type='Rodent' AND created_date >= '2025-01-01T00:00:00'
  &$select=date_trunc_ym(created_date) as month,count(*) as complaint_count
  &$group=date_trunc_ym(created_date)
  &$order=month ASC
  &$limit=24

DOHMH inspection results by borough (all-time)

GET https://data.cityofnewyork.us/resource/p937-wjvj.json
  ?$select=borough,result,count(*) as inspection_count
  &$group=borough,result
  &$limit=50

What time period does the 311 data cover?

The 311 complaint figures cover 1 January 2025 through the pull date of 2026-06-25. June 2026 data is partial (through 2026-06-25). Earlier periods are not included in this report; the full historical record from 2010 is available directly from NYC Open Data.

What do the inspection result categories mean?

The DOHMH inspection dataset uses the following result categories (per DOHMH's Rat Inspections: Terms and Practices guidance):

• Passed — no evidence of active rats or conditions that attract rats.
• Failed for Rat Activity — active rat signs found (fresh burrows, runways, rub marks, or gnawing).
• Failed for Other Reason — harborage conditions present (clutter, dense vegetation, standing garbage) without active rat signs.
• Failed for Rat Activity and Other Reason — both active rat signs and harborage conditions.
• Bait applied — rodenticide was applied during the inspection visit.
• Monitoring visit — follow-up visit to assess progress after a prior failure.
• Stoppage done — burrows or entry points were physically stopped during the visit.
• Cleanup done — sanitation or debris removal was conducted.

What are the known limitations of this data?

• 311 complaints reflect reporting behavior, not absolute infestation levels. Higher complaint counts in a borough may partly reflect a more active 311-using population rather than strictly more rats.
• ZIP code neighborhood labels are informal. ZIP code boundaries do not align cleanly with neighborhood boundaries in New York City. Labels used in this report are common informal designations.
• DOHMH inspection data is all-time (not 2025-specific). The inspection dataset includes records from all years available in the dataset, not just 2025–2026. Year-filtered inspection queries are available directly from NYC Open Data.
• Borough labels in the 311 dataset are self-reported or geocoded by the 311 system. A small fraction of records may have misclassified boroughs or null borough values; these are excluded from aggregates.
• The June 2026 monthly count is partial (data through 2026-06-25). Annual comparisons should account for the incomplete period.
• Rat Mitigation Zone designations are sourced from DOHMH public documentation. The complete and current list of designated zones is maintained by the NYC DOHMH Rat Mitigation Zones portal.

How do I reproduce this analysis?

All queries listed above can be run directly against the NYC Open Data Socrata API at no cost. The API requires no authentication for read operations. The full NYC 311 dataset can also be downloaded as a CSV from the dataset page.