Mouse or Rat? Here’s How to Know for Sure
Not sure whether you’re dealing with mice or rats? It’s more common than you’d think — especially if all you’ve noticed are scratching sounds or a few droppings. But getting the ID right matters. Rats and mice behave differently, enter homes differently, and often need different traps or treatment plans.
This guide will help you tell them apart by looking at the key signs: from size and droppings to behaviour and where they tend to hide.
Key Differences at a Glance
| Feature | Mouse | Rat |
|---|---|---|
| Size | 6–10cm body (excluding tail) | 20–25cm body (excluding tail) |
| Tail | Long, thin, about same length as body | Thicker, shorter tail relative to body |
| Droppings | Small (3–6mm), pointed ends | Larger (10–20mm), capsule-shaped |
| Behaviour | Curious, fast-moving, light-footed | More cautious, heavier, noisy |
| Entry points | Can squeeze through 5mm gaps | Need from 15mm, usually over 20mm to get in |
| Common areas | Lofts, kitchens, behind appliances | Under decking, in walls, around bins or sheds |
Appearance
The most obvious giveaway is size. Adult rats are significantly larger than mice and tend to look more robust. Mice are small, quick, and tend to have large ears and a pointed nose. Rats have smaller ears in proportion to their head, and a blunt snout. Their tails also differ — a rat’s tail is thick, scaly, and shorter relative to its body.
Droppings
One of the clearest signs is what's left behind. Mouse droppings are tiny and pointed at both ends — often found near food sources or along walls. Rat droppings are much larger and more sausage-shaped. If you’re spotting droppings under sinks or in loft spaces, the shape and size can tell you what you’re dealing with.
Sounds and Movement
Think you’ve heard something scurrying? Mice make lighter, quicker sounds and often scratch or rustle behind walls or in ceilings. Rats tend to move more slowly but make louder noises — thuds, gnawing, or dragging. Their size makes them harder to miss once they’re inside.
Where Are You Seeing Activity?
Rats and mice have different habits. Mice love small indoor spaces: behind the fridge, airing cupboards, or even inside drawers. Rats are more likely to burrow under decking, tunnel along garden walls, or enter through damaged drains. If you're seeing holes near the compost heap or around sheds, rats are the more likely culprits.
Entry Points & Damage
Mice only need a 5mm gap to get inside — that’s about the size of a pencil. Rats need larger holes (20mm or more) but will chew through wood, plastic, or even soft metal to make their own entry points. If you notice gnawed bin lids, chewed pipes, or soil pushed away near foundations, rats could be to blame.
Why It Matters
The control methods you use depend on whether you're dealing with mice or rats. Traps, bait stations, and proofing products vary in size and strength. For example, mouse traps aren’t strong enough to deal with a rat. And the placement of bait stations changes depending on their behaviour.
- Need to control mice? See our mouse control guide
- Think it’s rats? Read our rat control guide
Final Thoughts
Telling the difference between rats and mice isn’t always obvious — but once you know what signs to look for, the picture becomes clearer. Size, droppings, behaviour, and where you’re seeing activity are all strong clues.
We go to great lengths to ensure that all our pest control products are effective, fast & easy-to-use. You may also find our expert mouse guide or expert rat guide useful if you want to learn more about getting rid of rodents from your home or business.
