Some mice can make cute, fun pets, but the house mouse is not one of those. And when a rodent creeps into your home through a crack or gap or gnaws on drywall, stored boxes, and paper, or even wiring to make its nest—while urinating and dropping feces as it travels, it can be a danger and health hazard to your family.
But because mice are small, nocturnal, and nest in out-of-the-way places, you may not even know you have a problem until the population gets large and you have a major problem.
Small, with a slender body, its physical characteristics include:
- Body length: 2 - 3 1/4 inches
- Tail: 3 - 4 inches long and hairless
- Weight: less than 1 ounce
- Color: usually light brown to gray
- Head: small with small black eyes, pointed snout and large ears
- Mice are nocturnal, meaning they are most active at night—when most of your family is asleep.
- It is so flexible that it can get into your home through a crack or hole as small as 1/4-inch.
- A mouse can jump as high as a foot, and climb 13 inches up smooth, vertical walls.
- It can run 12 feet per second and swim as far as 1/2 mile.
- Being very inquisitive, a mouse will nibble or feed on any available human food, as well as other household items, such as paste, glue or soap.
- It does not need free water but can survive on the water in the food it eats.
Although mice will rarely run in the open during the day (unless you have a major infestation), they do leave signs of their presence. Look for:
- Dead or live mice.
- Nests or piled nesting materials.
- Gnawed holes in stored foods, piled papers, insulation, etc.
- Food scraps or wrappings left behind.
- Excreted droppings - 1/4 - 1/8 inch with pointed end or ends.
- Rodent hairs.
- Runways—indicated by narrow pathways where dust and dirt have been swept clean, grease marks are noticeable, urine trails seen under black light.
You might also:
- Hear it skittering on hardwood or laminate floors.
- Smell the fetid odor of a large infestation.
Disease and Damage: Why Are Mice a Problem?
According to the CDC, mice and rats spread more than 35 diseases directly to humans through handling; contact with rodent feces, urine, or saliva; or rodent bites. Humans can also contract diseases carried by rodents indirectly, through ticks, mites or fleas that have fed on an infected rodent.
A few of the diseases that can be carried or transmitted by mice are:
- Rat bite fever
- Lymphocytic choriomeningitis (aseptic meningitis, encephalitis or meningoencephalitis)
- Tapeworms and ringworm-causing organisms
Mice are also a problem because of the damage and mess they leave behind.
- They have no bladder control, so they trail urine wherever they walk.
- Mice leave behind 50 to 75 droppings each day.
- A single female mouse can reproduce up to 35 young each year.
- They cause structural damage through gnawing and nest-building.
- Mice feed on and contaminate foods with urine, droppings, and hair.
- In the U.S., mice cause more than $1 billion in damage each year.
Now that you know how to tell if you have mice and the problems they can cause you'll need to rodent-proof your home.