Deer Mouse, Peromyscus maniculatus; White-footed Mouse, Peromyscus leucopus
Deer Mouse. Photo by David Cappaert, Michigan State University, Bugwood.org.
IPM Steps to Reduce Deer Mice and White-footed Mice
1. Sample for Pest
Confirm the presence of these pests.
Where to find it while inspecting: Note: Important ways Peromyscus varies from House Mouse—deer mice and white-footed mice are semi-arboreal, so you need to inspect high as well as low for entry points. These two tend to forage outside and keep harborage inside. Inspect along walls and corners for signs of rodent activity. Mice tend to run along walls and use the same routes each time. Crawl spaces of all sorts and suspended ceilings are common sites of habitation. 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. Peromyscus tend to nest in cavities. The nest consists of fibrous (usually vegetative) materials and may be lined with fur, feathers, or shredded cloth. They nest at or just below ground level or in buildings. Peromyscus only need openings of 1/4".
2. Proper ID
Before you act, determine what species of rodent, specifically mouse, is in your building.
Size and Particulars: 3–4" plus 2–5" tail. The two species are difficult to tell apart. They are markedly bi-colored (including the tail) with white undersides and reddish-brown (gray in immatures) upper portions. In comparison to House Mouse, Peromyscus have larger eyes and ears and lack the musky, mousy odor.
3. Learn the Pest Biology
Knowing the life cycle and habitat needs helps you fight these pests.
Life Cycle: Peromyscus reach sexual maturity in 7–8 weeks, gestation is usually 21–23 days and young are weaned at 2–3 weeks. Typically 2–4 litters per year (possibly more in warm climates) with 3–5 per litter.
Preferred Food Sources: They prefer seeds and grains but will eat most anything. They tend to eat small amounts often and commonly cache food.
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. Typically forages outside and nests inside.
4. Determine Threshold
Your threshold for mouse 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 with rodent-resistant materials. Remember their semi-arboreal nature when looking for and closing openings. 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.
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:
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.
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.