Droppings identification guide
Size is the first clue, shape is the second and where you found them is the third. Most people mix up two pairs: mouse and bat, which are the same size, and mouse and rat, where young rats can confuse things.
| Animal | Size | Shape and look | Usually found |
|---|---|---|---|
| House mouse | 3–6 mm | Like a grain of rice with pointed ends, dark, scattered | Kitchen cupboards, drawers, loft, behind appliances |
| Brown rat | 10–20 mm | Capsule or sultana shaped, blunt ends, often in groups | Along walls and runs, loft, under decking, sheds |
| Grey squirrel | 7–10 mm | Barrel shaped, rounded ends, lighter brown | Loft, often in one spot near the entry |
| Bat | 4–8 mm | Like a mouse dropping but crumbly, with shiny insect bits | Piled under a roost, stuck to walls, by gaps at the eaves |
| Cockroach | 1–3 mm | Like ground pepper or coffee grounds, or small ridged pellets | Warm spots: behind fridges, cookers, boilers |
| Bed bug | About 1 mm | Black dots that smear like ink when wiped | Mattress seams, bed frames, headboards |
| Birds | Varies | White and chalky with a dark centre, splashed | Loft near the eaves, window sills, below nests |
Mouse or bat droppings?
Both are a few millimetres long and dark. The difference shows when you crush one with a stick or a gloved finger: mouse droppings are hard or go smeary, while bat droppings crumble into a dry powder that glints with insect wing fragments. Bats roost in lofts but don't chew or nest, and their roosts are protected by law, so it matters which you have. See bats in the loft.
Mouse or rat droppings?
Rat droppings are two to four times longer, with blunter ends, and tend to collect in groups along the routes rats use. A pile of small droppings and a few big ones usually means rats of mixed ages, not mice and rats together. See our guides to mice and rats.
Fresh or old?
Fresh rodent droppings are dark, glossy and soft. After a few days they dry out, go dull and crumble. Clear an area, check again in two days, and you'll know if the activity is current.
Cleaning up safely
Rodent droppings and urine can carry diseases including leptospirosis and salmonella. Wear disposable gloves. Don't sweep or vacuum dry droppings, because that puts dust in the air. Spray them with disinfectant, leave for five minutes, wipe up with paper towels, bag and bin them, then wash your hands.
Questions people ask
How many droppings means an infestation?
Any fresh rodent droppings mean activity. A mouse can leave dozens in a night, so numbers alone don't tell you how many animals there are. Droppings in several rooms, or reappearing after you've cleaned, point to an established problem.
Can I just vacuum them up?
It's better not to. Vacuuming dry droppings can put dust into the air. Dampen them with disinfectant first, then wipe up with gloves on.
I found droppings but haven't heard anything. Is that possible?
Very. Mice are quiet, and many people find droppings long before they hear a thing.