Brown Rat

Where it lives

Burrows in soil banks, under sheds and rubble walls, along wied (valley) beds, in sewers and beneath ground-floor slabs. Rarely far from food waste and water.

Signs

• Dark tapered droppings 15–20 mm long, often in runs
• Smooth greasy smear marks along walls, pipes and beam edges
• Gnaw damage to cables, packaging, doors and plastic pipework
• Burrow entrances 7–12 cm across near walls, drains and rubble
• Scratching and running sounds in ceilings, walls and roof voids at night

Risks

• Transmits Leptospirosis (Weil’s disease), Salmonella, Hantavirus and Toxoplasma
• Gnawed electrical cabling is a documented cause of building fires
• Contaminates food stock and packaging, forcing costly disposal
• Undermines paving, drainage and foundations through burrowing
• Automatic failure point in any food safety audit

Prevention

• Seal every gap larger than 20 mm. Rats get through far less than people expect
• Keep refuse in rodent-proof bins with closed lids, away from the building
• Repair defective drains, gullies and manhole covers
• Cut back vegetation and clear rubble against external walls
• Never leave pet food, bird feed or compost accessible overnight
• Check the drain runs. A defective interceptor under the yard is the most common way rats get into an otherwise sound building

Treatment

We survey to find the harbourage and entry routes, then combine tamper-resistant bait stations, break-back trapping and, most importantly, physical proofing so the population cannot return. Rodenticide use follows the CRRU stewardship rules: never placed in the open, always recorded, and removed once activity ceases. A typical programme is three to four visits over six weeks.