The rodent Mus musculus, commonly known as the house mouse, is one of the most persistent and invasive pests in North America. The presence of mice can be unnerving to some; many people are frightened by the sight or even signs of a mouse in the home. Their tendency to get into food stored in cupboards and pantries, pollute areas of the home with urine and feces, as well as their ability to reproduce quickly, make them a particular nuisance. Mice are extraordinarily resilient; properly eliminating them requires knowledge and experience of mice and their habits.

 Understanding mice

    The mouse has lived alongside humans for thousands of years, thriving in and around residential homes and commercial structures. They are capable of doing a considerable amount of damage; a mouse will consume about 3 grams of food per day, but they destroy a considerable amount more than they eat, contaminating it with fecal matter, urine and fur. In agricultural areas, they are capable of ruining massive amounts of food; the World Health Organization estimates that mice destroy around 33 million tons of food per year. Mice may carry a variety of diseases; in addition they can transmit many other diseases indirectly through ticks, fleas or mites that live on infected rodents.

    In the home, mice look for an undisturbed location to nest; this could be a wall cavity, attic, garage, basement or even an unused cabinet or dresser. Mouse nests will be lined with materials such as shredded paper or bits of cloth; deer mice may also use feathers or fur. Mice will usually nest somewhere near a food source - in residential homes, this usually means the kitchen. If you have seen evidence of mice in the kitchen, chances are the nest is within ten feet of that spot. Mice can squeeze their bodies through extremely small openings and move from room to room at places where pipes or wires penetrate the wall, if such places are not sealed off properly. Mice will generally try to stay out of the open, but if they do venture out they tend to keep one side of their body pressed against the wall, as this gives them a sense of direction and security since their eyesight is not good. They explore their territories daily in their search for food and are known to be very curious. 

    Mice can reproduce at an astounding rate. Under the right condition, a female mouse can have up to ten litters per year, each litter averaging about of 3-14 pups; this means that, in theory, a single pair of mice could multiply into the hundreds within a single year. Their high rates of reproduction makes it incumbent upon homeowners to ensure that any attempts to deal with a mouse infestation are capable of eliminating (not just reducing) the population.

Signs of mice in the house

     There is one reason and one reason only why mice have taken up residence in or around your home: a readily available food source. Their nest location is determined by its proximity to their food source; this is usually in the home near the kitchen, but can be outdoors as well (thick vegetation, wood piles and debris near the house are common nesting sites). Mice are attracted to grains and cereals primarily, but they also like chocolate, especially if it is made with peanut butter. Cereal boxes gnawed around the edges, bags of crackers or granola ripped into and finding chocolate bars half-eaten are all sure signs of mice. Another visible sign of mice is their distinctive droppings and urine stains they leave behind. Mouse droppings are narrow and pointed, usually about 1/8" to 1/4" in length (this is a good way to distinguish mice from rats, as rat droppings are considerably longer and have blunted ends). Mice will also leave "rub marks" or smudges along the wall sides and floors along their commonly used trails. Mouse urine is phosphorescent and will show up under a blacklight.  Most homeowners with mouse problems also hear squeaking, gnawing or scuttling noises from the walls at night; it is not uncommon to find tooth marks from gnawing on baseboards, trim and the bottoms of cabinets.

    Since mice are always looking for food, they tend to foul up areas of the kitchen where food is stored or prepared, or even where things have come in contact with food. For example, it is not uncommon to find droppings in silverware drawers, food preparation areas, tupperware drawers, in the pantry and around the stove. Mice are constantly defecating and urinating when they move, so the presence of droppings is the surest indicator of where mice are active.

How to get rid of mice

    When it comes to mice, conventional, individual trapping is the first thing many people attempt. It is not difficult to catch a few mice using individual traps, but trapping usually is not sufficient to deal with larger mouse infestations. For one thing, most homeowners do not start trapping until they have already found evidence of mouse activity in their home (feces, urine trails, cereal boxes with the corners gnawed, etc.); unfortunately, by the time this happens the mouse problem has usually become so critical that laying a few traps is no longer sufficient to handle it. Another factor is that many homeowners do not know how to place traps effectively; successful trapping requires a knowledge of the habits and movements of mice in order to place the traps in the best locations. Finally, individual trapping is unable to eliminate an entire population, which is especially important given the mice's ability to reproduce quickly. In fact, pregnant females will seldom venture out during their gestational period, which means you are very unlikely to catch them by individual trapping. Mice also leave pheromone trails behind wherever they go; pheromone trails are chemical indicators that attract other mice, even after the mouse that left the trail has been removed. Any removal efforts will be ineffective unless all mice in the area can be eliminated. Individual trapping is an effective indicator for the presence of mice in an area, but is not a suitable technique for eliminating entire populations in most circumstances.

     In order to remove an entire population, something is needed that can both take care of existing mice and exclude any future mice from getting into the home. Creature Control technicians are experts in identifying rodent entry points, locating nesting areas, and removing and excluding mice to keep your home mouse-free. Our technicians will begin by talking with you about the activity you have witnessed, followed by a thorough foundation to roof-line inspection (including the attic) which will identify entry points, nesting sites and potential problem areas. Our technicians will give quotes for repairing entry points, suggest environmental changes and install tamper-resistant rodenticide bait stations to eliminate the existing mouse population.

    For those who may prefer a non-lethal means of removal, we also offer whole colony trapping, a form of collective trapping that is able to remove an entire nest without any of the downsides of individual trapping, and without killing the mice. In some cases these colony traps are the best means of removal, and whether to use them is decided on a case by case basis.

    To schedule a mouse inspection, or for more questions about our removal and exclusion process, call the rodent experts at Creature Control at 1-800-441-1519.

Common behaviors that increase rodent activity

     In many cases, mouse activity is encouraged by certain human activities that create conditions conducive to rodents. Some of these activities include: 

• Boxed food stored on the ground in pantries
• Woodchips against the foundation of the house
• Pet food left out in the open
• Unsanitary living conditions
• Standing water anywhere in the house (except the sump basin)
• Improperly stored garbage or trash bags left out
• Garage doors left open at night

CALL THE MOUSE EXPERTS AT CREATURE CONTROL TODAY! 1-800-441-1519

Mice in the News

Lansing area woman diagnosed with lymphocytic choriomeningitis from contact with mice

A Lansing area woman has become the first person in Michigan to be diagnosed meningitis caused by a rare infection called lymphocytic choriomeningitis virus (LCMV). LCMV is a frequently unrecognized cause of aseptic meningitis and congenital infections that is associated with the common house mouse. However, until recently most cases of LCMV in humans were caused by exposure to infected hamsters because humans have more direct contact with hamsters (often kept as pets) than with mice, even though the virus is more common in the house mouse.

The infected woman checked herself into a Lansing-area hospital with severe headache, body aches, photophobia (sensitivity to light), weakness, and fatigue. After conducting a whole series of tests, the woman was diagnosed with acute meningitis. Several more diagnostic tests confirmed that the cause of the meningitis was an LCMV infection. This got the attention of the CDC, since LCMV infections are relatively rare in humans.

The Michigan Department of Community Health immediately investigated for possible contact with rodents. Upon investigation, it was found that the family had owned 2 healthy pet rats for 2 years (although the patient had little direct contact with them). However, the patient reported that the family had been battling a severe rodent infestation for 6 months, since they no longer kept cats as pets. The family had been trapping 4–5 mice per night in the weeks before the woman fell ill. No other family members reported illness.

After obtaining permission from the patient, the Department of Community Health conducted a field study to determine the degree of the infestation and prevalence of the virus in the rodents living in and around the Lansing-area home. In one week, the Department caught 23 mice, 1 shrew and 1 chipmunk in the home. Post-mortem testing on the mice showed the presence of LCMV in 96% of the specimens.

Besides of obvious lesson of the uncleanliness of mice, this case demonstrates the importance of keeping a mouse problem from becoming an outrageous mouse infestation. Many people think getting a cat is a solution for mice in the house. Animal removal specialists disagree, pointing out that cats can only catch mice who are out in the open and are incapable of getting to mice where they live: in wall voids and attics. Getting a cat is a popular remedy for mice, especially in predominantly rural areas such as Lansing, Mason, Pinckney and much of Ingham County. However, when dealing with mice the best thing to do is to call a wildlife control company who can deliver effective mouse control using rodenticides capable of wiping out entire mouse populations.

Click here for the CDC report on this case.

Article from the Grand Rapids Examiner reports mice attack in nursing home

The Grand Rapids Examiner reports a strange incident in which mice swarmed and attacked an elderly man in a nursing home in Australia. The Karingal home is an elder care facility that is home to 70 residents, 22 of whom are over the age of 90. But it was the story of an unidentified 87-year-old war veteran that uncovered the type of care residents of Karingal were actually receiving when it came to light that the man was attacked by swarms of mice in his bed.

The veteran was found bleeding from bites to his ears, neck and hands, and according to press reports, was so traumatized he had to be sedated with morphine. The veteran was not the only victim of mice attacks; apparently, the entire facility was overrun by vermin. This is an example of what can happen in situations where caretakers wait too long to contact animal removal professionals.