Rat droppings are dark brown or black pellets, 12 to 19mm long, shaped like large grains of rice. Brown rat droppings have blunt ends; black rat droppings are smaller and tapered.
Key takeaways
- Brown rat: 12-19mm, thick, blunt ends.
- Black rat: 7-14mm, thinner, tapered and curved.
- Mouse droppings: 3-8mm, pointed ends.
- Fresh droppings are dark and shiny; old ones grey and crumbly.
- Wear gloves; never touch bare-handed.
What Do Rat Droppings Look Like?
Dark pellets about the size of an olive stone, usually found in clusters along walls, in cupboards or near food sources. Fresh ones look moist and shiny; old ones dry out and turn grey.
Identification Guide: Brown Rat vs Black Rat vs Mouse
Brown rat (Rattus norvegicus, the common UK rat): droppings 12-19mm long, 3-4mm thick, with blunt or rounded ends, sometimes one end tapering to a point. Dark brown to black, often containing fur from grooming.
Black rat (Rattus rattus): droppings 7-14mm, thinner, with tapered ends and often a slight curve like a tiny banana. Much rarer in the UK, mostly in port areas.
House mouse: droppings 3-8mm, thin with sharp pointed ends, like grains of rice. If the pellets are under 8mm, think mouse first.
Watch out for lookalikes: rabbit droppings are rounder and uniform; water vole droppings (7-10mm) are rounded at both ends and found near waterways, not in houses.
How Fresh Are the Droppings?
Fresh droppings are soft, moist and shiny black. Within days they harden and dull; old ones are grey, crumbly and odourless. Fresh droppings mean active rats right now; only old ones suggest the problem may have moved on. A brown rat produces up to 40 droppings a day, so quantity tells you about numbers.
Where Do You Find Them Indoors?
Check behind appliances (fridges, washing machines), under sinks, in lofts, along skirting boards, in garages and sheds, and near pet food or bird feeders. Outdoors, look by compost heaps, under decking and around drain covers.
Other Signs You Have Rats
Droppings rarely come alone. Listen for scratching at night in walls and ceilings. Look for gnaw marks on wood, cables and packaging (a fire risk), greasy smear marks along skirting from rat fur, burrows in the garden, and a strong ammonia smell.
What To Do If You Find Rat Droppings: Step by Step
First, do not dry-sweep: it raises infected dust. Wear gloves and a mask, spray the area with disinfectant, wipe up with paper towels and bin them in a sealed bag. Disinfect all surfaces and utensils nearby and throw away any opened food packets.
Next, find how they got in. Rats squeeze through gaps as small as 25mm: check air bricks, pipe entries, gaps under doors and broken drains. Block holes with wire wool and sealant or cement. Remove food sources: sealed bins, no pet food left out, bird feeders on trays.
What Diseases Do Rat Droppings Carry?
Leptospirosis (Weil’s disease), salmonella and hantavirus can spread from droppings and urine. Food contamination is the main household risk.
When to Call Pest Control
Call a professional if you find repeated fresh droppings, hear nightly activity, or cannot find the entry point. Many councils offer pest control services; private firms give free surveys. Do not rely on ultrasonic repellers, which evidence shows do not work.
Preventing Rats Long Term
Make your home unattractive to rats: store food in sealed containers, keep bins shut with tight lids, clear fallen fruit in gardens, and move compost heaps away from the house. Bird feeders should have trays to catch spill, which is a major rat attractant.
Maintain the building envelope: repair broken air bricks, fit bristle strips to doors, cap unused chimneys, and keep vegetation trimmed back from walls. A yearly perimeter check each autumn, before rats seek winter shelter, prevents most infestations.
Rats and the Law in the UK
Under the Prevention of Damage by Pests Act 1949, local authorities can require landowners to deal with infestations. Tenants should report rats to landlords promptly; landlords are generally responsible for structural entry points, while tenants handle hygiene.
If you use poison, follow the label exactly and consider secondary poisoning risks to owls, cats and dogs. Snap traps in secure boxes are often the safer domestic choice; glue traps are now banned for public use in England.
FAQ
How many droppings per day?
Up to 40 a day for a brown rat.
Do they smell?
Fresh ones smell foul and musky.
Can old droppings make you ill?
Yes; damp-wipe, never dry-sweep.
What do baby rat droppings look like?
Smaller versions of adult ones.
Should I call pest control?
For repeated fresh droppings, yes.
How do I stop rats returning?
Block holes, seal food, shut bins, clear clutter.
