House Mouse, Mus musculus

IPM Steps to Reduce House Mice

1. Confirm the presence of these pests.

House mice can contaminate food, transmit disease and cause allergies. You can reduce the chance of having house mice and if you see one, you need to act now.

Where to find it while inspecting: Inspect along walls for signs of rodent activity. Mice tend to run along walls and use the same routes each time. All rodent pests will leave droppings, urine stains, as well as “smudges” (grease marks) where their oily fur consistently comes in contact with walls and woodwork. Look for gnaw marks and damaged goods. DROPPINGS: mouse droppings are small 1/8" to 1/4" long are have pointed ends. (Rat droppings are 1/2" to 3/4" long with blunt ends.) Activity will be much more pronounced at night and you will be able to hear activity. Mice prefer nest sites in burrows under ground or under rubbish or debris, in basements and only need openings of 1/4".

2. Proper ID

Size and Appearance: 3.5"–3.75" plus 2.75"–4" tail. Smooth gray fur, lighter on belly. Smooth, semi-naked tail.

3. Learn the Pest Biology

Knowing the life cycle and habitat needs helps you fight these pests.

Life Cycle: Mice reach sexual maturity at 35 days, gestation is around 19 days and young are weaned at 3–4 weeks. Average 8 litters per year with 5–8 per litter.

Preferred Food Sources: They prefer seeds and grains but will eat most anything. They tend to eat small amounts often.

Preferred Habitat: Dark, secluded, undisturbed areas with abundant material for nesting, and are adaptable to indoor or outdoor sites, preferring to be close to a food source.

4. Determine Threshold

Your threshold for mice infestation is likely very low. You need to act

Threshold: Act when you see one mouse.

5. Choose Tactics

IPM for indoor pests is always a combination of exclusion and sanitation: Try to keep them out. Don’t provide water, food and shelter if they enter your building.

Best Management Practices: Eliminate harborage and food sources through sanitation. Remove clutter, search for openings in the building and block them. Keep all food items in containers and practice good sanitation to remove crumbs and grease residue.

Treatment Methods: Traps or bait must be placed close to nest or food areas but out of reach of children. Continue to set traps or sticky traps and plan to monitor in various susceptible sites. Effective sanitation and exclusion is the basis for successful treatment. Trapping must be ongoing and must be checked often. Poisons are not recommended.

6. Evaluate

Was the tactic successful? Record the date pests were first noted, and the tactic you used, and its success. Use one of our RECORD KEEPING tools

For More Information:

Evict and Exile Mice from Your Home

Maine.gov Got Pests: Mice

Schools Integrated Pest Management (IPM) for Rats and Mice

Burt, W. H., and R. P. Grossenheider. 1976. A Field Guide to the Mammals, Houghton Mifflin, Boston. 289 pp.

Timm, R. M., and W. E. Howard. 1994. “White-footed and deer mice” in Prevention and Control of Wildlife Damage, S. E. Hygnstrom, R. M. Timm, and G. E. Larson, ed.

Remember:

When a pesticide application is necessary, all necessary and required precautions are taken to minimize risk to people and the environment and to minimize risk of pesticide resistance or pest resurgence. Pesticide use in your school may be prohibited or regulated by local policies or state and federal regulations. Risk reduction methods can include, but are not limited to, spot-treatment, the use of gel or paste bait formulations placed in inaccessible locations, injection into a crack or crevice, and other methods that reduce potential exposure.