As outdoor temperatures become colder, mice seek locations that are more hospitable.
In many cases, that most agreeable location is inside a home, according to John Hobbs, agriculture and rural development specialist with University of Missouri Extension.
“No matter how big a house is, it is never big enough for most people to want to share it with a mouse,” said Hobbs.
Mice contaminate food for humans and livestock consumption, damage structures and property, and transmit diseases such as food poisoning and dysentery.
There are even cases of fires getting started when mice gnawed through insulation surrounding electrical wires.
Droppings, fresh gnawing, tracks and nest material are signs of mouse activity in a house or barn. According to Hobbs, effective mouse control involves mouse proof construction, good sanitation, and population reduction by traps and poison baits.
He recommends first eliminating places where mice find shelter. If they don’t have places to rest, hide, or build nests and rear young, they cannot survive in large numbers.
“Although good sanitation will seldom eliminate mice, poor sanitation is sure to attract them and will permit them to thrive in greater abundance,” said Hobbs.
The best permanent form of controlling mice is to mouse-proof places where food is stored, processed or used. According to Hobbs, if you are building a new home, there are also some steps that can be taken to “build them out.”
“A mouse can enter a home through any opening larger than one-quarter of an inch,” said Hobbs. “If you discover some holes, fix them quickly and appropriately.”
Trapping is another proven method of mouse control. The simple wood-based snap trap and most bait traps (with peanut butter, dried fruit or a small piece of bacon for bait) are effective.
Set traps close to walls, behind objects, in dark corners and in places where there is evidence of mouse activity. Hobbs also recommends using enough traps to make the effort decisive.
“Leaving traps baited but unset until the bait has been taken at least once also reduces the chance of creating trap-shy mice,” said Hobbs.
Single-dose or multiple-dose rodenticides can be effective in reducing large numbers of mice. The multiple-dose baits are considered much safer to use than the single-dose poisons.
“Remember, these products are designed to kill mice. Dead mice stink. So be careful when and where you use mouse and rat poisons. There are no known rodenticides that do not present some hazard to animals other than rodents,” said Hobbs.
As with any pesticide, always read and follow the label. It is a good idea to use rubber gloves or tongs to remove the carcass.
For more information on controlling mice, contact your local University of Missouri Extension center or go online to http://extension.missouri.edu to obtain a copy of guide sheet G9442, “Controlling House Mice.”