**Wharf Rats** is a common name for the **Norway Rat** (*Rattus norvegicus*), particularly those found near waterfronts, ports, and wharves. They are large, stocky rodents. The conflict is **disease, contamination, and structural damage**: they infest docks, ships, warehouses, and adjacent urban areas, contaminating goods, transmitting numerous severe diseases (historically including the **Bubonic Plague** via fleas), and causing significant infrastructure damage by gnawing and tunneling in soil and structures.
Taxonomy and Classification
Wharf Rats belong to the Class Mammalia, Order Rodentia. They are highly successful commensal rodents, living closely associated with humans.
Physical Description
Adults are large, 18 cm to 25 cm long body.
- **Appearance (Key ID):** Stocky, blunt nose, small ears, and a scaly tail that is usually shorter than the head and body combined; usually brownish-gray fur.
- **Damage ID (Key):** Large droppings (blunt, capsule-shaped); gnaw marks on wood, plastics, and pipes; visible burrows and tunnels in soil or along seawalls; greasy rub marks along their travel paths.
- **Conflict:** Public Health, Structural, Nuisance.
Distribution and Habitat
Cosmopolitan, found globally, especially in urban areas and ports. Habitat is basements, sewer systems, burrows in soil, garbage dumps, and storage areas near water sources.
Behavior and Conflict
The conflict is their gnawing and disease vectoring ability.
- **Gnawing:** Constant gnawing on hard materials (including electric cables and pipe insulation) to manage their growing incisor teeth, leading to fire and flooding risks.
- **Reproduction:** High reproductive rate allows populations to rebound quickly after control efforts.
Management and Prevention
Management is **Sanitation and Exclusion**.
- Implementing rigorous garbage control; storing all food and feed in rodent-proof containers; quickly removing organic waste near docks and warehouses.
- **Rodent-proofing** structures (sealing holes larger than 1/2 in; use of anticoagulant rodenticides in tamper-resistant bait stations; strategic placement of snap traps.
Conservation and Research
Research focuses on studying the movement of rat populations between ship and shore, managing rodent populations in complex sewer systems, and developing effective resistance management strategies for chemical baits.