Methodology

What data sources does the Infestation Index use?

The Infestation Index uses the NYC 311 Service Requests dataset (ID: erm2-nwe9) from NYC Open Data, filtered to two complaint-type/descriptor combinations that together capture the primary pest complaint channels in NYC:

1. complaint_type = 'Rodent' — rat and mouse sightings and conditions, handled by NYC DOHMH.
2. complaint_type = 'UNSANITARY CONDITION' AND descriptor = 'PESTS' — insect/vermin complaints logged through NYC Housing Preservation and Development (HPD) and related agencies.

Why these two categories?

NYC's 311 system routes pest complaints differently depending on property type and pest category. Rodent complaints (rats, mice) are classified under complaint_type='Rodent' and routed to DOHMH. Insect and vermin complaints (cockroaches, bedbugs, flies, and other household pests) are typically classified as UNSANITARY CONDITION with descriptor PESTS. Together, these two categories represent the two largest pest complaint channels in the 311 system.

What queries were used?

-- Rodent total (Jan 2025–Jun 2026):
GET https://data.cityofnewyork.us/resource/erm2-nwe9.json
  ?$where=complaint_type='Rodent' AND created_date >= '2025-01-01T00:00:00'
  &$select=count(*) as total

-- PESTS total (Jan 2025–Jun 2026):
GET https://data.cityofnewyork.us/resource/erm2-nwe9.json
  ?$where=complaint_type='UNSANITARY CONDITION' AND descriptor='PESTS'
    AND created_date >= '2025-01-01T00:00:00'
  &$select=count(*) as total

-- PESTS by borough:
  &$select=borough,count(*) as count
  &$group=borough &$order=count DESC

What are the known limitations?

• UNSANITARY CONDITION covers more than insects. The broader category includes MOLD, SEWAGE, and GARBAGE sub-types; this index uses only the PESTS descriptor.
• Complaint counts reflect reporting access and behavior, not absolute infestation levels. Boroughs with large public-housing populations (which route complaints through separate HPD channels) may show different patterns than privately rented buildings.
• June 2026 data is partial (data through 2026-06-25).