Mice and rats are more than a nuisance. They chew insulation off wiring, they contaminate stored food, and they carry organisms — Hantavirus, Salmonella, Leptospira — that make people genuinely ill. They also breed fast enough that a small problem becomes a large one inside a season.

Signs worth acting on

• Droppings. Small, dark, tapered at one end. Fresh ones are shiny.
• Gnaw marks. On cable sheathing, timber corners and food packaging.
• Scratching at night. Usually in a wall cavity or above a ceiling.
• Nests. Shredded paper, loft insulation or fabric, tucked out of sight.
• A musky smell. Strong enough to notice in a confined space.

The three-stage job

1. Survey. We map the runs, find the entry points and photograph them.
2. Removal. Snap traps indoors, checked and cleared on a schedule. No rodenticide inside the building envelope.
3. Exclusion. Every gap over a quarter inch is packed with copper mesh and sealed. Door sweeps, vent screens and pipe collars where they are needed.

Exclusion is the part clients are tempted to skip because it costs more than the trapping. It is also the only part that ends the problem.

Afterwards

Droppings and nesting material are cleared with a HEPA vacuum and the area is disinfected — dry sweeping puts the contamination into the air, which is exactly what you are trying to avoid. We come back at four weeks to confirm the traps are cold and the seals have held.