Brown Rat vs. House Mouse

Attribute	Brown Rat	House Mouse
Scientific Name	Rattus norvegicus	Mus musculus
Size	Medium to large	Small
Color	Brown	Gray
Habitat	Urban areas, sewers, farms	Urban areas, fields, homes
Lifespan	2-3 years	1-2 years

Physical Attributes

Brown rats, also known as Norway rats, are larger in size compared to house mice. They can grow up to 10 inches in length, not including their tail, which can add another 7 to 9 inches. Brown rats have a more robust body with a blunt nose and small ears. On the other hand, house mice are much smaller, typically measuring around 2 to 4 inches in length, with a tail that is about the same length as their body. House mice have a more slender body with a pointed nose and large ears.

Color and Fur

Brown rats have coarse fur that is typically brown or gray in color, with a lighter underside. Their fur can sometimes have a reddish tint as well. House mice, on the other hand, have softer fur that is usually light brown or gray, with a lighter belly. Some house mice may have a slightly yellow or off-white coloration as well. Both species have fur that helps them blend into their surroundings, providing them with some level of camouflage.

Habitat and Behavior

Brown rats are typically found in urban areas, sewers, and basements, as well as in fields and farms. They are excellent climbers and swimmers, allowing them to access a wide range of environments. Brown rats are omnivores and will eat almost anything, including grains, fruits, vegetables, and even other small animals. House mice, on the other hand, are more commonly found in homes, barns, and other buildings where they can find food and shelter. They are also omnivores and will consume a variety of foods, including grains, seeds, and insects.

Reproduction

Brown rats have a shorter gestation period compared to house mice, with a pregnancy lasting around 21 to 23 days. A female brown rat can have up to 12 litters in a year, with each litter consisting of 7 to 14 pups. This high reproductive rate allows brown rats to quickly populate an area. House mice, on the other hand, have a slightly longer gestation period of about 19 to 21 days. A female house mouse can have up to 10 litters in a year, with each litter containing 5 to 6 pups. While house mice reproduce at a slightly slower rate than brown rats, they can still quickly establish a large population in a favorable environment.

Health Risks

Both brown rats and house mice can pose health risks to humans. They can carry and transmit diseases such as leptospirosis, hantavirus, and salmonellosis through their urine, droppings, and saliva. In addition, their constant gnawing can cause damage to property and pose a fire hazard if they chew on electrical wires. Brown rats are also known carriers of fleas, ticks, and mites, which can further spread diseases to humans and pets. House mice, on the other hand, are known to contaminate food and food preparation surfaces with their droppings and urine, leading to potential foodborne illnesses.

Control and Prevention

Controlling and preventing infestations of brown rats and house mice require a combination of methods. This includes sealing off entry points to buildings, removing potential food sources, and using traps or baits to capture or kill the rodents. It is important to address any infestations promptly to prevent the rodents from reproducing and spreading further. In some cases, professional pest control services may be necessary to effectively eliminate a large infestation of brown rats or house mice.