Mice vs rats: how to tell the difference
Last updated: 12 October 2026 · Reviewed by: M. Hanifi, RSPH Level 2 qualified technician
Mice are small (7–10 cm body) with large ears and leave small pointed droppings (3–6 mm); rats are much bigger (up to 25 cm body), with blunt droppings 10–20 mm long. Mice live mostly indoors and nest near food, while rats often come from gardens or drains. Both need treatment and proofing.
Mouse or rat? Side-by-side comparison
The quickest way to tell is by droppings: small and pointed means mice, large and blunt means rats.
| Feature | House mouse | Brown rat |
|---|---|---|
| Body length | 7–10 cm | 20–25 cm |
| Droppings | 3–6 mm, pointed | 10–20 mm, blunt |
| Ears | Large relative to head | Small, close to head |
| Gap needed | About 6 mm | About 15 mm |
| Typical location | Kitchens, walls, floors | Gardens, drains, lofts |
| Behaviour | Curious | Cautious of new objects |
Why the difference matters
Rats and mice need different trap sizes, bait placement and proofing, and rats often point to a drainage problem.
Related pages
Frequently asked questions
Can you have mice and rats at the same time?
Yes, although rats often keep mice away. We identify both during the inspection.
