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BEASTS BEGONE! Appendix A: Animal Identification

Norway Rat

Stocky (approximately 1 lb.), grayish brown, with a long, rather hairless tail. Largely (but not exclusively) nocturnal. Frequent invader of basements, wall voids, attics, crawl spaces, and human living spaces of buildings.

Access Routes

Physical cover near the foundation can facilitate access; check firewood stacks, debris piles, and crawl spaces under decks or additions.

Entry Sites

Holes larger than 1/2 inch, usually in vicinity of foundation. Also accesses crawl spaces and wall voids via attached garages.


Squeaking. Scampering; gnawing.

Gnaw Marks and Food Remains

Gnaw marks on wood, plastic, etc.


Not as musky as house mouse.


Back and sides of animal: each hair partitioned into black, gray, black segments; 1/2 to 3/4 inch long.
Belly: white to gray, approximately 1/8 inch long.

Fecal Droppings

Dark, elongated; 1/2 to 3/4 inch long.

Other Signs

Body rub marks around entry sites and along runways. Runways in attic insulation. Burrows in ground near foundation and dirt floors of basements.
Nests (may be lined with shredded fibrous material). Urine stains (under UV light)

Tracks: norway rat tracks  Front: 1 in.  Hind: 1 in.

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