Kansas City is among the top 25 cities for rodent activity and since the pandemic started rodent populations have markedly increased. This is largely due to lowered levels of human activity and a change in food availability. Along with the increase in rodent populations, cases of leptospirosis and salmonella have spiked, being spread directly by rodents. Other illnesses such as Lyme disease, rickettsialpox, and typhus are spread by the fleas, ticks, and mites that live on mice and rats. In fact, rodents are vectors for up to 200 different human pathogens.

Not only do they carry diseases to which humans are susceptible, they can cause damage to homes through urination, defecation, gnawing, and nest-building. They leave urine stains on walls and feces along travel lines. They will chew anything available for nesting materials such as wood, paper, clothes, or insulation. Rodents will also chew to open gaps through which they will enter or travel through the home. Nesting sites often include upholstered furniture, walls, inside vehicles, or even the lining of electrical appliances. Their activity has been known to damage electrical wiring, creating a fire risk.

Mice and rats excel at gaining entry into human dwellings. Rodents are so flexible that if one can fit its head through an opening, it can fit its entire body through. This means that a rat needs a gap no wider than a quarter. For a mouse, the opening only needs to be as wide as a dime. Such gaps are frequently found around utility lines, windows and doors, attic or crawl space vents, and around the foundation. Copper mesh can be used to plug such entry points. (Steel wool may be used, but is more complicated to apply effectively and is prone to rust.) Rodents are excellent climbers and will easily scale a wall with even a slight texture. Wall surfaces such as stucco, brick, and even many sidings are readily climbable. Sealing gaps is important even in the roof among rafters and eaves. They will also climb trees and bushes and use the limbs as a bridge to the home, so it pays to keep vegetation trimmed away from the building.

Rodents will typically enter homes in search of food and shelter. Mice get most of their water from their food. As such, they can survive several months without drinking water, but only a few days without food. Food should be stored in metal, glass, or thick plastic containers with tight-fitting lids. Spills should be cleaned immediately and dirty dishes should never be left out. Pet food can be particularly attractive to rodents and shouldn’t be left out overnight. If trash and food waste is stored inside, it should be in rodent-proof containers and should be cleaned regularly with soap and water. 

It’s also important to consider is how we can control mice and rats outside the home. If local populations are low outside, the risk of entry is low as well. Outdoor cooking areas such as barbecues should be kept clean and bird feeders should be kept away from the house and be outfitted with squirrel guards to limit rodent access. It’s not all about food, however. Possible nesting sites can be eliminated as well. Wood piles should be kept away from the house and elevated more than a foot from the ground; grass and shrubberies within 100 feet should be kept well-trimmed.

Once rodents begin breeding within the home, populations can skyrocket alarmingly. Reproductive maturity in mice begins at six to ten weeks and a female can birth up to ten litters per year. After three weeks of gestation, a litter of five or six pups is born. In ideal conditions, a single pregnant mouse can turn into 8,000 mice in one year. Keeping rodents at bay is no small task and if an infestation sets in, professionals should be contacted to bring the situation under control.