Rat Scat Identification: Norway Rat Droppings and Tracks

Rodent droppings are small and dark; shape and size are the first cut (rice-grain with pointed ends for mice, blunt and larger for rats, oval pellets for squirrels and voles). Tracks show four toes on the front foot and five on the hind, and most rodents bound, so the larger hind prints land ahead of the front prints. Gnaw marks with paired incisor grooves are often the clearest sign. The measurements below for Norway Rat are quoted from the wildlife agencies linked at the bottom of the page.

• Size: Up to 0.75 inches long, about 0.25 inches in diameter
• Shape: Blunt and rounded at both ends
• Contents/color: Fresh droppings are relatively soft in texture
• Where: A single mouse produces about 40-50 droppings per day, often clustered in small piles

• Gait: Tracks and tail-drag marks often appear on dusty surfaces or in mud

• Gnaw marks: Norway Rat gnaw marks are about 1/16 inch wide
• Burrow entrance: An active burrow entrance is 2-3 inches wide, clean around the opening, with mouse hair visible
• Grease/oil smudge marks: Grease and dirt from a rat's/mouse's body rub off onto beams, rafters, pipes, and walls, leaving marks

House Mouse droppings are slender and tapered at both ends, about 0.25 inches long; Norway Rat droppings are larger and blunt-rounded at both ends (0.5-0.75 inches) The House Mouse page has its own sign list.

The Norway Rat is somewhat larger than the Roof Rat

Human contact with the urine, droppings, and saliva of rats (including Norway Rats) can spread hantavirus If you need to clean it up, wear gloves and a mask, wet it down first, and bag it; see the CDC guidance linked in the sources.

Put something of known size next to it (a coin, a pen, a boot) and shoot straight down in soft light; low side light brings out the shape of tracks in mud or snow. For scat, photograph the whole deposit and one close-up showing contents. Note where it was: on a log, in the open, on a trail, near water. The app suggests the likely animal; confirm with the size and shape notes above.

Rat scat is dark, capsule-shaped and much larger than mouse droppings. The Internet Center for Wildlife Damage Management (ICWDM) gives Norway rat droppings as up to 3/4 inch long and 1/4 inch in diameter with blunt ends, and says a Norway rat leaves about 40 to 50 droppings a day, usually clumped in small groups (the scat summary above attributes that daily figure to a mouse; ICWDM gives it for the Norway rat). Other descriptions:

• Fox Pest Control: about 1/2 inch long and 1/8 inch wide, capsule- or raisin-shaped with blunt ends, dark brown to black.
• Fantastic Pest Control (UK): oval with slightly pointed ends, 1 to 2 cm, dark brown or black and shiny.
• The Wildlife Trusts (UK): light brown to black, slimy and soft, with an unpleasant smell of urine.

Where you find them matters too: along walls and rat runs, near food and pet food, in kitchens, attics, basements and crawl spaces, and behind appliances (UC IPM; Fox Pest Control).

The two common house rats leave different droppings. ICWDM describes roof rat droppings as about 1/2 inch long with pointed ends, against the Norway rat's larger, blunt-ended droppings up to 3/4 inch. Burrows are a second clue for Norway rats: ICWDM describes active burrow entrances 2 to 3 inches wide, clean of debris, with rat hairs around the opening.

The animals differ in size as well. UC IPM gives roof rats 5 to 10 ounces and Norway rats 7 to 18 ounces; ICWDM describes the roof rat as 6 to 8 inches long with a 6- to 8-inch scaly tail.

• Mouse droppings: much smaller, about 1/8 to 1/4 inch, skinny with pointed ends; Fox Pest Control compares rat droppings to raisins and mouse droppings to rice grains.
• Squirrel droppings: usually lighter, brownish or reddish, and found in attics or near trees (Fox Pest Control); Fantastic Pest Control notes squirrels tend to go in one spot while rats scatter droppings.
• Water vole droppings (UK): smaller than rat droppings, rounded at both ends, putty-like, green, brown or purple, and without a strong smell (The Wildlife Trusts).
• Hedgehog droppings (UK): about 5 cm long, cylindrical, dark, often with bits of insects (The Wildlife Trusts).
• Bat and cockroach droppings: see the indoor droppings section of our animal poop identification chart.

Fresh rat droppings are shiny, dark and soft or moist; older ones turn hard, dull, gray and crumbly (Fox Pest Control; Fantastic Pest Control). ICWDM notes fresh Norway rat droppings are soft in texture.

Because a Norway rat leaves 40 to 50 droppings a day in small groups (ICWDM), a single dropping is unusual. It may be old, from an animal passing through, or from something else entirely. Look for the other signs ICWDM and UC IPM list: gnaw marks about 1/16 inch wide, greasy smudge marks along regular routes, tracks in dust, burrows under garbage cans and compost, nests in cluttered garages and woodpiles, and gnawed fruit or nuts in the yard.

The CDC's steps for rodent urine and droppings:

• Put on rubber or plastic gloves.
• Spray the droppings with a bleach solution (1.5 cups of household bleach in 1 gallon of water, or 1 part bleach to 9 parts water) or an EPA-registered disinfectant until very wet, and let it soak for 5 minutes.
• Do not sweep or vacuum droppings, urine or nesting material; the CDC says this can put tiny droplets containing viruses into the air.
• Wipe up with paper towels and throw them in a covered garbage can that is emptied regularly.
• Wash your hands with soap and warm water after removing the gloves.

Fox Pest Control lists hantavirus, salmonella and leptospirosis among the diseases linked to rat droppings, and The Wildlife Trusts' advice for any droppings is never to touch them. If you feel unwell after contact with rodent droppings, see a doctor and mention the exposure.

The sections above were added on 2026-09-25. Research and drafting used AI assistance, and every measurement was checked against ICWDM, UC IPM, the CDC, The Wildlife Trusts, Fox Pest Control and Fantastic Pest Control, opened and read that day.