Rat or Mouse? How to Tell the Difference

Droppings

• Rats: up to 2 cm long, spindle-shaped, in defined places along walls
• Mice: 3–6 mm, rice-grain shaped, scattered widely including inside cupboards

Traces on the building

• Rats: dark greasy smear marks on repeated routes, burrow holes outside, larger gnaw damage
• Mice: fine gnaw marks on packaging, shredded paper or textile nests, small entry gaps from about 6 mm

Sounds and behaviour

Mice are typically heard as light scurrying and scratching in walls and ceilings at night. Rats produce heavier, slower sounds and are more often noticed in basements, courtyards and around drains.

Why the difference matters

Rat problems usually involve an external cause: a drain defect, an open bin store, a gap in a foundation. Control needs to address that route, not only the animals present.

Mouse problems are more often about many small entry gaps and indoor food sources, which changes both the placement of traps and the sealing work afterwards.