Mouse droppings are small and dark, about an eighth to a quarter inch long, with at least one pointed end, a bit like a grain of rice. They show up in drawers, cabinets, behind appliances, along baseboards and in garages. Because mice forage close to their nests, droppings usually mean the nest is within a few feet to a few yards. Clean them up wet with disinfectant, then find and seal the gaps the mice use.
What mouse droppings look like
University of Kentucky pest training describes house mouse droppings as 1/8 to 1/4 inch long with at least one pointed end. Fresh ones are dark and slightly shiny. Older ones are dull, dry and gray.
Mice also leave a lot of them. The same training notes mice make 20 to 30 visits to food sources each night, so even a few mice can leave droppings all over a pantry shelf.
Mouse or rat?
Size is the quickest check. Rat droppings are much larger: about half an inch for roof rats and three quarters of an inch for Norway rats. If the droppings look like rice grains, it is mice. If they look like small olive pits or raisins, it is rats.
Gnaw holes help too. Mouse holes are about an inch across and clean-cut. Rat holes are about two inches with rough edges. See rat droppings identification.
Droppings or something else?
A few things get mistaken for mouse droppings:
- Cockroach droppings are smaller and often look like ground pepper or coffee grounds
- Bat droppings collect in piles below a roost, often in an attic or near a gable vent, and crumble easily
- Seeds, burned rice and debris can look similar in a dark cabinet
If you are not sure, take a close photo next to a coin and ask a technician.
How many mice do you have?
Droppings in one drawer can mean one curious mouse. Droppings in several rooms, behind several appliances and in the garage usually mean an established group. University of California guidance says a female can have 5 to 10 litters a year with about 5 or 6 young each, and the young mature in 6 to 10 weeks.
University of Kentucky training says mice usually forage within 10 to 25 feet of their nest, sometimes only a few feet when food is easy. So droppings cluster near the nest. Follow the heaviest concentration and you are usually close.
Want a local technician to take a look?
(901) 256-2861Cleaning up mouse droppings
Follow the CDC's method: gloves, 30 minutes of airing out, soak droppings with disinfectant or a fresh 1-to-9 bleach solution for 5 minutes, wipe up with paper towels, bag them, and disinfect the surface. Do not sweep or vacuum.
Throw away food in chewed or soiled packaging. Wash dishes and utensils that were in a contaminated drawer. Wipe shelves and cabinet floors before restocking. See droppings cleanup.
Places to check in a Memphis home
Mouse droppings collect wherever mice feed and travel. In Memphis homes, check:
- Silverware and utensil drawers, especially the back corners
- Under the kitchen sink, around the pipes
- Behind the stove, fridge and dishwasher
- Pantry shelves and the floor under them
- Laundry rooms, near the dryer vent
- Garage shelves with seed, pet food or grass seed
- The attic edges, near the eaves
- Closets on exterior walls
In older homes on crawl spaces, kitchen and bathroom cabinets over plumbing chases are the most common spots. In newer slab homes, the garage is usually where it starts.
Urine and smell
Mice also leave urine, which you may not see. Heavy activity can produce a stale, musky smell in cabinets or closets. Under a blacklight, rodent urine stains can show up as faint marks along runways, though other things glow too.
Treat urine spots the same way as droppings: soak with disinfectant, wait, wipe and bag. Wash any fabric or bedding that may have been soiled in hot water.
If the smell stays after cleanup, mice may still be active nearby, or there may be a nest or a dead mouse in a wall or cabinet void. Check again in a few days, and follow the heaviest droppings back toward the wall to find where they enter.
Finding where the mice get in
University of California guidance says mice can squeeze through openings slightly larger than a quarter inch. In Memphis homes, look first at:
- Gaps around pipes under kitchen and bathroom sinks
- The space behind the stove, dishwasher and fridge
- Garage door bottom corners
- Dryer vents and gaps around AC lines
- Crawl space vents and plumbing chases in older homes
Seal with metal, mesh or concrete; plastic, rubber, foam and wood are not suitable, according to the same guidance. See mouse control and steel wool vs copper mesh.
Want a local technician to take a look?
(901) 256-2861