Rats or Mice? How to Tell Which You Have

Hearing scratching at night or finding droppings in a cupboard is bad enough, but the first question most people ask us is: is it rats or mice? It matters, because the two behave differently, carry different risks and need a different approach. Here is how to tell which one you have.

Check the droppings

Droppings are usually the clearest clue.

• Mouse droppings are small – roughly the size of a grain of rice – thin, with pointed ends. You will often find lots of them scattered around, because mice go wherever they please.
• Rat droppings are much bigger – around the size of a raisin or olive stone – thicker, and often blunt at the ends. They tend to be found in groups along the routes rats use regularly.

Listen to the noise

Mice make light, quick scratching and scurrying sounds, often in ceilings and cavity walls. Rats are heavier: you may hear thumping, gnawing or something being dragged, typically under floors, in the loft or behind kitchen units.

Look at the damage and marks

• Gnaw marks: mice leave small, neat nibbles; rats leave larger, rougher marks and can chew through plastic, wood and even soft metal pipes.
• Smear marks: rats leave dark, greasy rub marks along skirting boards and walls where they run regularly. Mice rarely leave obvious smears.
• Holes: mouse holes are small and neat; rat holes and burrows outside are around 6–9cm across.

Where you are finding signs

Mice are happy high up and indoors – lofts, kitchen cupboards, behind appliances and in wall cavities. Rats are more likely to come in from outside, often through drains, under doors or from the garden, and are commonly found at ground level, under floors and around sheds and outbuildings. That said, rats will happily climb into lofts too.

If you have actually seen one

A house mouse is small, around 7–10cm long, with large ears and a long, thin tail. A brown rat is much bigger – its body alone can be 20cm or more – with a blunter nose, smaller ears and a thick, scaly tail. A young rat can be mistaken for a mouse, so if in doubt look at the size of the head and feet, which are noticeably larger on a rat.

Why it makes a difference

Mice are curious and will investigate anything new, while rats are cautious and often avoid unfamiliar objects for days. That is one reason shop-bought treatments that work on mice often fail on rats. Rats also tend to point to a bigger problem, such as a damaged drain, which needs finding and fixing or they will keep coming back.

Still not sure?

You do not need to work it out on your own. One of our RSPH-qualified technicians can carry out a free survey, identify exactly what you have, find how it is getting in and give you a fixed written price before any work starts. We visit discreetly, in unmarked vans.

Read more about our rat control and mouse control services. We cover homes and businesses across Staffordshire, Cheshire and Derbyshire, including Stoke-on-Trent, Leek, Macclesfield and Crewe.

Call 07971 571 171, freephone 0800 999 7378, or book a free survey online.