Rat Population in Hong Kong: Estimated ~2.4 Million (Roughly 1 Per Human)

The estimated rat population in Hong Kong is approximately 2.4 million—roughly on par with the human population (~7.5 million, but concentrated in dense urban areas where rats thrive).

Context

• Species: Primarily Norway rat (Rattus norvegicus) (sewers, burrows) and Roof rat (Rattus rattus) (buildings, vegetation).
• Density: Among the highest in the world due to:
  • Extreme urban density (high-rises, wet markets, refuse).
  • Subtropical climate (year-round breeding).
  • Extensive sewer/drainage network.
  • Abundant food waste.

Control Efforts

• Food & Environmental Hygiene Dept (FEHD): Rodent control teams, baiting, trapping, inspections.
• Rodent Infestation Rate (RIR): Monitored district-by-district; target <3%.
• Public campaigns: "Keep Clean, No Rat" education, waste management.

Challenges

• High-rise buildings: rats travel via pipes, cables, voids.
• Construction disturbance displaces colonies.
• Resistance to anticoagulant rodenticides.

The 2.4M figure is an estimate (extrapolated from trapping indices); exact counts are impossible. But "one rat per person" is a widely cited urban ecology benchmark for dense tropical cities.