Close up head on shot of a mouse

Is it a mouse or a rat?

There may be two sides to every tale, but do you know a mouse tail from a rat tail? Visually, you may be able to easily identify a mouse from a rat – when they’re standing still! But when these disease-carrying rodents are on the move or hiding, sometimes the only way to know for sure what you’re dealing with is to identify them by their droppings or a specific trait. 

So what are some of the key identifiers that can help you tell the difference between these two home-invading pests? Check out our list below.

illustration of a mouse and a rat

  House Mouse Norway Rat
Color/Length (without tail) Gray to light brown; light brown chest; 2¾ to 4 inches Coarse brown with black fur; gray or white chest; 7 to 10 inches
Nose, Ears, and Eyes Pointy nose; small ears and eyes; color blind Blunt nose; small ears and eyes; color blind
Tail Same length as body; nearly hairless with rounded scales Shorter than body; 
hairless with rounded scales
Habitat Urban and suburban areas, close to humans offering a food source and shelter Urban and suburban areas, close to humans offering a food source and shelter
Food Source Mostly fruits, seeds and grains such as cereal, occasionally meat Neophobic: avoiding anything they are unfamiliar with such as baits. Prefer unspoiled foods: grains, fish, nuts, and meats
Droppings ¼ inch long; rod-like with pointed ends ¾ inch long; rounded ends
Behavior Nocturnal, forage at dusk and night; excellent climbers; nest in attics, garages, and basements Nocturnal, forage at night; excellent swimmers; create burrows; use sewers as access points; nest in basements and garages
Life Cycle Gestational period 19-21 days; birth litter of 3-14; 5-10 litters a year; lifespan 1-3 years Gestational period 21 days; birth litter of 7-14; 4-6 litters a year; lifespan 1-3 years


signs of mice

Signs you have mice

  • Holes in food packaging or other types of packaging
  • Nesting material: ripped paper, cardboard, clothing or other fibrous material
  • Nest: ball of soft, shredded material about 5 inches in diameter
  • Tooth or scratch marks on wooden baseboards, cabinets, window panes, doors, etc.
  • Grease marks (rubs) on walls, baseboards, cabinets, window panes, doors, etc.
  • Droppings: pointed, seed-shaped; about 1/4 inch long; black and wet when fresh, grayish and dry when old
  • Tracks: less than an inch; four toes on front paws and five in back
  • Chewed insulation or electrical wiring (potential fire hazard)
  • Scratching sounds within walls

rat near pipe

Signs you have rats

  • Holes in food packaging measuring approximately 2 inches in diameter
  • Tooth or scratch marks on wooden baseboards, cabinets, window panes, doors, etc.
  • Chewed electrical wire, piping or insulation (creates a potential fire hazard)
  • Chewed sheet metal, lead pipes or concrete
  • Grease marks left on walls, baseboards, and entry points from their fur rubbing
  • Droppings: dark pellets with blunted ends, about 3/4 inch in length
  • Tracks: four toes on the front feet and five on longer, hind feet; claw marks and/or tail marks often visible

How are rodent-borne diseases transmitted?

Rodents are known to spread more than 35 diseases. About a dozen can be transmitted directly to humans, while the majority are spread indirectly. To avoid any exposure, you should familiarize yourself with the five primary ways that rodent-borne diseases can be transmitted.

  • Breathing in dust that is contaminated with rodent urine or droppings
  • Direct contact with rodents, their urine or droppings
  • Consuming contaminated food or water
  • Through a bite wound
  • Indirectly by being bitten by fleas, ticks, or mites that feed on infected rodents

Are rodents outwardly aggressive?

Rats can exhibit aggressive behavior when threatened, which is usually the result of fear-induced defensive behavior. Unlike rats, mice will not attack and prefer to avoid humans. However, mice may bite when they’re being handled.

Prevent rodents from entering your home

With their ability to reproduce at incredibly fast rates, time is of the essence to avoid costly damage, dangerous contamination, and the risk to your family or business. The sooner you identify a rodent issue, the better. Western Exterminator pest specialists are experts in rodent prevention, treatment, and exclusion and can protect your home and family from the risks associated with these destructive, disease-carrying pests. Contact us today if you suspect you have a rodent problem.

Tiffany Tenley

As a Marketing Content Manager, Tiffany has come to love and appreciate the diverse and complex world of pests—good, bad and ugly. Not only does she research and write about them, she admits to having eaten a few crickets on some cheese-laden nachos. When she's not working, Tiffany enjoys spending time with her family, exploring new restaurants, concert-going, reading, writing and traveling.



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