Beasts Begone! Appendix A: Animal Identification
Small (usually less than 1 oz.), dark, flying mammals. Nocturnal. Frequent invader of attics and wall voids. Occasionally enter basements and human living spaces.
Since bats are flying animals, no specific access routes (besides a relatively clear flight lane) are needed.
Usually on the upper portion of the structure. Any opening larger than a 1/4 inch has potential as an entry site. Common locations include roof drip edges, dormer tie-ins, roof corners, chimneys, vents, deteriorated roofs, walls, and eaves.
High-pitched, rapid clicking. Scratching in walls, attics, etc. Fecal Droppings
Dark, elongated, granular, 1/4 to 1/2 inches long, crumbles into dust (actually insect parts) when rubbed between two fingers. Often confused with mouse droppings, which are more tapered at the ends and hard (won't crumble).
Distinctive, acrid, musty odor (from large colonies in particular).
Dark, brown, or gray; 1/8 to 1/4 inch long.
Urine stains; body rub marks (especially at heavily used entry sites).