You have probably seen a cartoon or stereotypical TV show where someone sees a mouse and says, “Eek, a mouse!” Mice and rats around homes and farmsteads can be a problem. Have control methods improved on the typical snap trap of 50 years ago? In short, they have.
The adult house mouse is about 5½ to 7½ inches long, including the 3–4-inch tail. Norway rats are much larger, from 13 to 18 inches long, including the 6–8½-inch tail.
According to the Internet Center for Wildlife Damage Management (ICWDM), mice eat many types of food but prefer seeds and grain. They sample new foods and are considered “nibblers.” Foods that are high in fat, protein, or sugar (e.g., bacon, chocolate, butter, nuts) may be preferred, even when grain and seeds are present. An individual mouse consumes about 1/10 of its body weight each day and up to 8 pounds per year. Mice contaminate far more food than they consume through their urine and feces.
Mice cause damage to structures through gnawing and nest-building. In livestock confinement facilities and similar structures, they quickly can cause extensive damage to insulation inside walls and attics. Such damage also occurs in homes, apartments, and commercial buildings.
Mice often damage large electrical appliances by chewing wiring and insulation, resulting in short circuits, fire hazards, and other costly malfunctions.
In homes and commercial buildings, mice may feed on stored food items and pet foods. They contaminate food with their urine, droppings, and hair. On farms, they damage structures that store feed and equipment. Mice often act as reservoirs or vectors of diseases, such as swine dysentery, leptospirosis, salmonellosis, and other diseases.
ICWDM suggests several preventive and control methods people can employ. Proper sanitation around structures is helpful. This reduces sources of food, water, and shelter. Rodent-proof construction is recommended, along with proper storage and disposal of refuse and garbage. They indicate that ultrasonic frightening devices are generally not effective. Repellants and toxicants are options to consider. Trapping devices, such as snap traps, cage or box traps, and glue boards may also be considered for use.
The Norway rat and the roof rat may also become problems on farms. During a recent drive through Shipshewana and surrounding areas, I saw corn cribs in use. It reminded me of when I was a boy when more farmers used corn cribs. These structures contain ear corn with spaces between sideboards or heavy galvanized steel wire sides to allow air circulation. Sloped roofs prevent most rainwater from entering the storage area. Rats were a common nuisance to these and other feed-containing structures on the farm.
Controlling rodents on farms consists primarily of two methods, traps and poison. Trapping technology has advanced considerably since the first snap traps were invented (although the snap traps still work). Multiple-capture live traps (also called curiosity traps) and covered bait stations with rodenticide are options. Read and follow all label directions. Sensing technologies can allow users to monitor capture events right from their cell phone.
If you stick with the old-style snap traps for either mice or rats, ICWDM recommends baiting the traps with peanut butter, marshmallows, hot dog, bacon, or nutmeat tied securely to the trigger. They wrote that although mice are not as afraid of new objects as rats, leaving the traps baited but unset until the bait is taken at least once will reduce the chance of mice escaping and becoming trap-shy. Also, when placing traps, place the trap perpendicular to a wall so that the rodent will step on the trigger end if walking along the wall.
ICWDM provides research-based wildlife damage information. For more information, visit their website at https://icwdm.org/.