IdentificationModerate risk
How Do I Tell a Rat From a Mouse?
Quick answer
Rats are much larger than mice, with thicker bodies, bigger heads and feet, and droppings about 10–20 mm long. Mice are small, around 6–10 cm without the tail, with large ears relative to their head and droppings only 3–6 mm long. Droppings are often the easiest way to tell which rodent you have without seeing it.
Why this happens
Identification matters because rats and mice behave differently. Mice explore new objects and stay close to their nest; rats are cautious of new objects and travel further.
A young rat can be mistaken for a mouse. Compared with a mouse of the same size, a young rat has a bigger head and larger feet.
What you may be seeing
- Mouse droppings: 3–6 mm, rod-shaped, pointed ends, scattered.
- Roof rat droppings: 10–12 mm, spindle-shaped.
- Norway rat droppings: 18–20 mm, blunt capsules.
- Heavy thumping in the ceiling suggests rats; light scratching can be either.
What you can do
When professional help may be needed
If you cannot identify the rodent or find where it is getting in, a professional inspection can confirm the species and entry points.
Related pest
Rats
Introduced rodents that live alongside people, nest in roofs, walls and gardens and gnaw through building materials and wiring. Roof rats are the most common household rat in many Australian cities.
Mice
Small, curious rodents that squeeze through tiny gaps, nest in walls, cupboards and appliances and breed quickly. The introduced house mouse causes most household problems.
Species mentioned
Roof Rat (Black Rat)
Rattus rattus
An agile climbing rat that nests in roof voids, trees and dense vegetation. The rat most often heard in ceilings in Brisbane and other coastal cities.
Norway Rat (Brown Rat)
Rattus norvegicus
A large, heavy-set burrowing rat found around drains, creeks, sheds and under slabs. Less of a climber than the roof rat.
Related questions
Related guides
Rodent-Proofing Your Home
How rats and mice get in, which materials actually keep them out, and how to combine exclusion with sanitation and trapping for lasting results.
GuideHow to Pest-Proof Your Home
A practical, room-by-room approach to reducing pests without relying on chemicals: remove what attracts them, close the ways in, and make your property less comfortable for them.
GuideCommon Brisbane Household Pests
A Brisbane-specific overview of the pests residents meet most often, when they are active, and what the subtropical climate, storms, creeks and Queenslander homes mean for pest pressure.
Local information
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Sources & further reading
- Australian Museum — insects and spiders — Australian Museum
- Queensland Health — mosquito-borne disease and environmental health — Queensland Health
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