You are sitting at home and all of a sudden a little gray rodent with relatively large ears and small black eyes scurries across the room! It is about 1/2 ounce in weight and if an adult 5 1/2 to 7 1/2 inches long, including its 3 – 4 inch tail. Of course, you must know by now that I am describing a house mouse. The house mouse is considered one of the most troublesome and economically important rodents in the United States. They can cause damage to property and transmit diseases such as salmonellosis and swine dysentery. You will know you have mice if you see small droppings, fresh gnaw marks and mouse nests made from fine shredded paper or other fibrous material. They are active mostly at night, but can occasionally be seen during daylight hours. Mice are excellent climbers and can jump 10 inches from the floor to a flat surface; they can squeeze through openings slightly larger than 1/4 inch in diameter. They can also survive a 9-foot drop and climb up most vertical surfaces.
Exclusion is the most common in the fight against house mice. Prevent mice from entering buildings by eliminating openings that are 1/4” or larger. Use sealants or mortar to help fill the gaps. Spray-in-place foams and steel wool pads will fill the gaps, but they won’t do much to stop mice from entering. Make sure doors, windows and screens fit tightly. Cover the edges of doors and windows with metal to prevent gnawing.
Population reduction is the last method for controlling mice. Traps and baits are two common population reduction methods. To ensure success with traps, you need to use a sufficient number of traps in areas where mice are living. Snap traps or multiple-capture traps can be used to capture mice. Double setting snap traps, placing two traps close to each other, will yield the best results in situations with high activity. Multi-catch traps can catch several mice at a time without resetting. Glue boards are another alternative to traps. These sticky boards catch and hold mice as they try to move throughout the home. Be sure to use sticky boards in locations where non-target animals or items won’t get stuck in them. If this does happen, use an oily material, like vegetable or mineral oil, to dissolve the sticky substance. To make the traps more appealing you can apply a food source such as peanut butter or a chocolate chip melted to the trigger or you can secure a cloth scented with a food source to the traps’ trigger.
Baits are another population reduction method. Be sure to read and follow all directions on baits. When choosing baits, consider the location and method of applications and any non-target pets and children. Choose the type of bait for your specific location and application. Mice have been known to move pelleted baits without eating them. Just because you have an empty box, doesn’t mean they have eaten the bait. Bait stations or bait blocks ensure that the critter actually ate the bait.
Use caution when cleaning up droppings, nests, or mouse remains. This can help to decrease the potential spread of diseases carried by mice like Hantavirus. Use protective waterproof gloves and spray the carcass and trap or nest with a household disinfectant or a 10% bleach solution. Use a sealable bag turned inside out to pick up the mouse. To remove feces or urine, spray the area with a disinfectant until wet and wipe up with a towel, rag or mop. Don’t use the vacuum or broom to collect dry feces as that can cause the material to go into the air and be inhaled.
For more information on mouse control, refer to NebGuide, Controlling House Mice that can be accessed at http://extensionpubs.unl.edu or through your local extension office.