Rat vs Mouse Droppings: How to Tell Which You Have in Arizona
Short answer: rice-sized droppings usually mean mice; half-inch droppings with pointed ends usually mean roof rats. Don't sweep or vacuum either one. Wet them with disinfectant first.
Rat Droppings vs Mouse Droppings: The Size Check
Rodent droppings are cylindrical with pointed to rounded ends, so shape alone won't settle it. Size will. Cornell University's Integrated Pest Management program gives these lengths:
- Mouse droppings: about 1/8 to 1/4 inch, like a grain of rice. Usually lots of them, scattered along walls, in drawers and under the sink.
- Roof rat droppings: about 1/2 inch, dark, with pointed ends. Found in the attic, garage, along block walls and near fallen citrus.
- Norway rat droppings: 3/4 to 1 inch and blunter. Less common in Phoenix-area homes than roof rats.
Fresh droppings are dark and soft. Old ones are gray, dry and crumble. If you clean an area and find new droppings there a day or two later, the rodents are still active.
Where You Find the Droppings Tells You Something Too
- Attic, rafters, top of the water heater closet: roof rats. They climb in at the roofline from citrus, palms, fences and utility lines (UA Extension).
- Kitchen drawers, pantry, under the sink: usually house mice, which get in low, under doors and around pipes.
- Garage, near pet food or birdseed: either one. Size decides it.
- A pile of sticks and debris in the yard, garage or engine bay: a pack rat nest. See rodent control for pack rats.
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How to Clean Up Rat and Mouse Droppings Safely (CDC Steps)
The CDC says not to vacuum or sweep rodent urine, droppings or nesting material, because that can put virus particles in the air. Its steps for a home or garage:
- Air it out first. Open doors and windows for 30 minutes and leave the area while it airs.
- Put on rubber or plastic gloves.
- Mix a fresh bleach solution: 1 part household bleach to 9 parts water (about 1.5 cups per gallon), or use an EPA-registered disinfectant.
- Soak the droppings. Spray until they are thoroughly wet and let them sit for 5 minutes, or as the label says.
- Wipe up with paper towels and put them in a covered trash can.
- Disinfect the surfaces nearby: floors, counters, cabinets and drawers.
- Wash gloved hands, take the gloves off, then wash your hands with soap and warm water.
Heavy droppings in an attic or insulation are a bigger job. University of Arizona Cooperative Extension treats cleaning up a severe indoor roof rat infestation as a health priority, and that is usually work for a professional.
Found Droppings? Rat and Mouse Removal in Phoenix
Cleaning up the droppings doesn't stop the rodents leaving them. A rodent visit maps how they're getting in (the roofline for roof rats, door gaps and pipe entries for mice), traps inside, sets locked, tamper-resistant bait stations outside where appropriate, and shows you which gaps to seal. A one-time diagnostic visit with treatment is $149. The plan is $50/month with treatment every 60 days and free callbacks. Start a plan the same day and your visit fee covers your first 3 months of the plan.
Hearing scratching overhead too? See roof rats in Arizona: signs and how to get rid of them, rodent control in Phoenix and pest control cost.
Rodent control in Phoenix · Mesa · Scottsdale · Tempe · Queen Creek · Peoria · Sun City · all service areas
Rat and Mouse Droppings: Questions
How can you tell rat droppings from mouse droppings?
Size is the quickest check. Cornell University IPM puts mouse droppings at about 1/8 to 1/4 inch long and roof rat droppings at about 1/2 inch. Norway rat droppings are bigger still, 3/4 to 1 inch. If most of what you find is the size of a grain of rice, it is likely mice; if it is closer to a raisin, it is likely rats.
What do roof rat droppings look like?
About half an inch long, dark and spindle-shaped with pointed ends (Cornell IPM gives roof rat droppings as about 1/2 inch). In Phoenix-area homes they usually turn up in the attic, the garage, along walls and near fallen citrus or pet food.
Is it safe to vacuum or sweep up mouse droppings?
No. The CDC says not to vacuum or sweep rodent urine, droppings or nesting material, because it can put virus particles in the air. Wet them first with disinfectant or a fresh bleach solution, let them soak for 5 minutes, then pick them up with paper towels.
What bleach mix does the CDC recommend for droppings?
The CDC recommends 1 part household bleach to 9 parts water (about 1.5 cups of bleach per gallon), mixed fresh, or an EPA-registered product labeled as a disinfectant. Spray until the droppings are thoroughly wet and let them soak for 5 minutes or as the label directs.
I only found a few droppings. Do I still have a problem?
Usually, yes. Rats and mice are rarely seen in daylight, so droppings are often the first sign. Fresh droppings are dark and soft; old ones are dry and crumble. Clean them up using the CDC steps, then check the same spot in a day or two. New droppings mean they are still active.
How much does rodent control cost in Phoenix?
A one-time diagnostic visit with treatment is $149. The plan is $50/month with treatment every 60 days and free callbacks. Areas outside our own service area are handled by a licensed, insured Arizona partner at the same posted prices.