Quick answer
Mice are small (7 to 10 cm body) with large ears, pointed noses and droppings of 3 to 6 mm. Rats are much larger (up to around 25 cm body) with blunt noses, small ears and droppings of 1 to 2 cm. Rats sound heavier, make bigger holes and are more cautious. Rats usually need stronger action and often a professional.
Hearing something in the loft or finding droppings in the kitchen leads to one question first: is it a mouse or a rat? The answer changes what you should do next, so it's worth taking a few minutes to check.
House mouse or rat: quick comparison
Use several clues together. Young rats can be mistaken for mice, so look at the head, feet and droppings as well as size.
| Feature | House mouse | Brown rat |
|---|---|---|
| Body length | 7 to 10 cm | Up to around 25 cm |
| Weight | Around 20 g | Up to around 500 g |
| Head | Small, pointed nose | Blunt, rounded nose |
| Ears | Large relative to head | Small, close to head |
| Tail | Thin, as long as body | Thick, scaly, shorter than body |
| Droppings | 3 to 6 mm, like rice grains | 1 to 2 cm, thicker, like large grains |
| Noise | Light pattering | Thuds, scraping, dragging |
| Holes | Small, around 2 cm or less | Larger, rough edges |
| Behaviour | Curious, explores new things | Cautious, avoids new objects |
Compare the droppings
Droppings are the most common clue. Mouse droppings are small, dark and pointed at both ends. Rat droppings are much bigger and often found in groups along runs.
Photograph droppings next to a coin for scale before cleaning them up with gloves and disinfectant.
Listen to the noises
Mice make light, fast scratching and pattering. Rats are heavy enough to produce thuds, scraping and dragging sounds, often in lofts, under floors and in walls.
Look at the damage
Mice nibble packets and leave small, neat holes. Rats gnaw through wood, plastic, soft metals and cables, leaving larger holes. Outdoors, rats dig burrows near walls, sheds and decking; mice rarely do.
Rats also leave dark greasy smear marks along walls and pipes where they run regularly.
- Burrows outside: rats
- Small nibbled packets: mice
- Gnawed cables and wood: more likely rats
- Grease marks along runs: rats
Why it matters
Mice can often be handled with good food storage, sealing gaps and deterrents. Rats are bigger, more cautious, cause more damage and carry more health risks, so they usually need faster and stronger action, and often a professional.
MintGuard peppermint deterrent can be used for both mice and rats, placed along runs in the kitchen, loft, garage and shed. Each placement lasts around 30 to 60 days. Follow the pack instructions and keep out of reach of children and pets.
What to do next
Once you know what you have, follow the right guide: how to get rid of mice in the house, or how to get rid of rats.
Common questions
How can I tell if I have mice or rats?
Check droppings (mice 3 to 6 mm, rats 1 to 2 cm), noises (mice light, rats heavy), and holes (rats make larger ones). Burrows outside suggest rats.
Is it a baby rat or a mouse?
Young rats have big heads and feet relative to their bodies, blunt noses and thick tails. Mice have pointed noses, large ears and thin tails.
Can mice and rats live together?
It's unusual. Rats can prey on mice, so they rarely share the same space.
Are rats worse than mice?
Rats usually cause more damage and carry more health risks, so they need faster action.
Do the same deterrents work for mice and rats?
Both rely on smell, so scent deterrents like peppermint are used for both, alongside sealing gaps and removing food.
Looking for a product? See our rodent repellent page.
Sources and further reading
Written by the MintGuard UK team
Researched from trusted UK sources and checked under our editorial policy. Last reviewed 26 October 2026.
