Why it matters
Mice and rats require different treatment approaches. Mice are curious — they investigate new objects, which makes them easier to bait and trap. Rats are neophobic — they're suspicious of anything new in their environment, which makes them harder to control. Knowing which you're dealing with determines bait placement, trap type and exclusion strategy.
Physical differences
- Mouse — small, 15–20cm including tail, light brown/grey, large ears relative to head, thin tail
- Roof rat (black rat) — medium, 30–40cm including tail, dark brown/black, large ears, tail longer than body, agile climber — found in roof voids
- Norway rat (brown rat) — large, 35–45cm including tail, brown, small ears, thick tail shorter than body, ground-dwelling — found in subfloors and gardens
| Feature | Mouse | Roof rat | Norway rat |
|---|---|---|---|
| Size (incl. tail) | 15–20cm | 30–40cm | 35–45cm |
| Droppings | 3–6mm, pointed | 10–14mm, pointed | 15–20mm, blunt |
| Tail | Thin | Longer than body | Shorter than body |
| Found in | Kitchen, cupboards | Roof void | Subfloor, garden |
Mouse vs roof rat vs Norway rat — quick comparison.
Droppings: the easiest identifier
Droppings are the most reliable sign and the easiest way to identify which rodent you have. Check along skirting boards, in cupboards, under sinks and in the roof void.
- Mouse droppings — 3–6mm, dark, pointed ends, shaped like a grain of rice. Many droppings scattered.
- Rat droppings — 15–20mm, dark, blunt ends, shaped like a raisin. Found in clusters along travel routes.
Other signs
- Gnaw marks — mice leave fine tooth marks; rats leave deep, obvious grooves. Rats can gnaw through wood, plastic and soft metal.
- Noises — mice make light scurrying sounds; rats make heavier thumping and scratching. Both are nocturnal.
- Nests — mice build loose nests of shredded paper and fabric; rats build more substantial nests in burrows or roof voids.
- Rub marks — rats leave dark, greasy smudges along walls and entry points from their fur.
- Entry points — mice can enter through gaps as small as 6mm; rats need 15–20mm gaps.
Treatment differences
Mice respond quickly to bait stations and traps placed along travel routes. Rats require more strategic baiting — placing baits in established travel paths and waiting for neophobia to subside (which can take several days). Both require exclusion work to prevent re-entry. Professional rodent control addresses the infestation and identifies and seals entry points.