About the Data

Why does Urban Pest Watch use a 3-year data window?

A single year of complaint data can reflect anomalies — unusually warm winters, changes in 311 app adoption, or agency staffing. Urban Pest Watch uses January 2023 – June 2026 (42 months) to distinguish genuine seasonal cycles from one-time spikes and to compute year-over-year comparisons with statistical context. The NYC 311 Service Requests dataset (erm2-nwe9) extends back to 2010, enabling even longer trend analysis for researchers who want to reproduce this work.

What drives the seasonal pattern in rodent complaints?

NYC's Norway rat (Rattus norvegicus) population is most active above approximately 4°C (39°F). As temperatures warm in spring and summer, rat foraging activity increases and burrow construction expands outdoors, generating more visible rat sightings and therefore more 311 complaints. Cold winters temporarily suppress above-ground activity without eliminating colonies — rats retreat to heated buildings and subway infrastructure. The CDC's rodent control guidance and NYC DOHMH both document this seasonal behavior pattern.

Why do insect/vermin complaints peak later than rodent complaints?

The Infestation Index (a companion site tracking pest type, not time) shows that NYC insect and vermin complaints under UNSANITARY CONDITION — PESTS peak in fall (October), while rodent complaints peak in early summer (June). The fall peak for insects likely reflects the indoor migration of cockroaches and other pests as outdoor temperatures drop — the same temperature change that suppresses outdoor rat activity drives insects indoors where they are more likely to be noticed and reported.

Is Urban Pest Watch affiliated with the City of New York?

No. Urban Pest Watch is an independent data monitoring project not affiliated with, endorsed by, or operated by the City of New York or any NYC agency. All data from NYC Open Data under the CC BY 4.0 license. Last pull: 2026-06-25.