Beasts Begone! Appendix A: Animal Identification
Small (less than 1 oz.) slender grayish brown rodent with a largely hairless tail. Largely (but not exclusively) nocturnal. Frequent invader of basements, wall void, attics, crawl spaces, and human living spaces of buildings. Particularly common in urban areas.
Physical cover near the foundation can facilitate access; check firewood stacks, debris piles, and crawl spaces under decks or additions.
Holes larger than 1/4 inch, usually in vicinity of foundation.
Squeaking. Scampering; gnawing.
Gnaw Marks and Food Remains
Gnaw marks on wood, plastic, etc.
Dark, elongated, hard; about 1/8 to 1/4 inch long. Most frequent in areas of most mouse activity.
White to gray; 1/8 to 1/4 inch long.
Urinary "pillars" (small mounds of grease, urine, and dirt). Body rub marks around entry sites and along runways. Runways in insulation. Nests (generally loosely woven balls of shredded fibrous material). Urine stains (under UV light).