Mice and Rats
Mouse on museum stagecoach (C. Sullivan, NPS)
House Mouse (P. J. Kelley, Insects Limited, Inc.) 
Mouse droppings (F. Ritchie NPS) 
Rat chew marks on a leather saddle (F. Ritchie NPS) 
Mouse damage to candle (T. Parker) 
Evidence of mice feeding on linden seeds (T. Parker) 
Evidence of mice chewing styrofoam cup (T. Parker)
Key resources for prevention and mitigation of mouse and rat infestation are provided here. Although there are other types of rodents that can wreak havoc on buildings and grounds, mice and rats are the primary rodents that will consistently seek harborage inside buildings and storage spaces. Information on other types of rodents, such as squirrels, is forthcoming.
How do I know if I have a mouse or rat infestation?
- NPS Conserve O gram 3/12, Identifying Mouse and Rat Damage in Museum Collections, National Park Service
How do I pest-proof my facility to prevent a mouse or rat infestation?
- Illustrated Guide to House Mouse Exclusion and Monitoring, Museum Pests Working Group
- NPS Rodent Exclusion Manual, National Park Service, Mechanical Rodent-Proofing Techniques, National Park Service
- Pest Proofing Tips for Building Owners, Managers and Staff, NYC Health – NYC.gov
Where can I find guidance about rodent exclusion for new construction?
- NebGuide G1530, Rodent-Proof Construction – Structural, University of Nebraska, Lincoln Extension – Institute of Agriculture and Natural Resources
- NebGuide G2017, Rodent-Proof Construction – Drains and Feeding Equipment, University of Nebraska, Linco
ln Extension – Institute of Agriculture and Natural Resources
How do I set up a trapping program to monitor for mice and rats?
- Rodent Trapping Tip Sheet, Museum Pests Working Group
- Trap Placement Diagram for mouse snap traps, Museum Pests Working Group
- NPS Museum Handbook, Part I, Museum Collections. Chapter 5: Biological Infestations, National Park Service
- Visit the Monitoring — Trapping for Rodents section of this site for more information.
What do I need to know to protect my health and safety when handling mouse- or rat-infested materials?
- NPS Conserve O gram 2/8, Hantavirus Disease Health And Safety Update, National Park Service
- Cleaning Up After Rodents, Centers for Disease Control and Prevention
Where can I find general guidance on IPM for rodent control?
- Corrigan, Robert M. Rodent control: a practical guide for pest management professionals. 2001.
Squirrels
There are multiple species of squirrels that can be nuisance pests. In some locations, certain species are protected. Be sure to work with the appropriate wildlife or other agencies to ensure that you follow legal laws.
Identification
Eastern Grey Squirrel
The Eastern Grey Squirrel may be grey, reddish-grey, or black in color. it is diurnal (active during the day). They measure 16-20 inches long and 1.25 to 1.75 pounds. The Eastern Grey Squirrel occupies a range of 2 to 7 acres. Eastern Grey Squirrels are known to do damage to electrical wiring, fascia and soffits, and to leave rub marks.
Red Squirrel
Red squirrels are smaller than grey squirrels, and diurnal (active during the day). They have a red coat and prefer pine forests.
Southern Flying Squirrel
Southern Flying Squirrels are 8 to 10 inches long with a membrane of skin stretched between front and rear legs, a line of demarcation between upper and lower coat, and a flattened tail. They are nocturnal. In some areas flying squirrels are protected, so it is important to verify species and check local laws pertaining to what actions are legal.
Delmarva Fox Squirrel
At 18 to 27 inches and 1.75 to 2.25 pounds, the silver grey Delmarva Fox Squirrel is larger and more terrestrial than the Eastern Grey Squirrel. It was delisted from the Endangered Species list in 2015, so check local laws to determine whether it is still be protected in your area.
Squirrel Nuisance Prevention
- Exclude at entrances/exits
- Consider removing bird feeders or using feeders that have squirrel deterrents
- Post “Do Not Feed the Squirrels” signage
- Pick up fruit/seeds/acorns from and/or around trees
- Cut tree limbs away from structures
Trapping
- Trap size: 18”x5”x5”
- Baits: Cereal, grains, nuts (peanuts), sunflower seeds, shelled corn, mixed peanut butter and oatmeal, or mixed peanut butter and molasses
- Traps must be checked daily
- Please check locality for any trapping laws
Birds
Pigeons and other birds can enter and create problems inside historic structures, but more problematic are their nests and carcasses, which contribute to dermestid infestations. For example, Christina Cain has also shared this Case Study from the Denver Museum of Art on an infestation derived from a bird carcass.
Visit the Bird Identification Fact Sheets on this site more information on specific bird species.
Many species of birds are federally and/or locally protected. Be sure to work with the appropriate wildlife or other agencies to ensure that you follow legal guidelines in dealing with avian pests.
Various bird deterrents are commercially available. Generally they operate in one of several ways…
Created 2017, Updated 2021