The answer to whether bats make scratching noises in the attic is yes, though the sound is often misunderstood. When bats inhabit a structure, particularly the attic or wall voids, their movements create audible disturbances that homeowners frequently describe as scratching or scuttling. These sounds result from the bats navigating and settling into their roosting areas. The presence of these noises is a strong indicator that a colony has taken up residence.
The Source of the Sound Why Bats Scratch
Bats are not rodents and do not chew on wood or wires, but they possess small, sharp claws on their feet and a prominent thumb-claw on each wing. These specialized appendages are used for climbing and anchoring themselves to rough surfaces like masonry, wood beams, and insulation. The perceived “scratching” sound originates from these claws dragging and catching as the bat crawls across materials to find the most secure and comfortable roosting spot. This movement is more of a light scuttling or a rapid, light scraping than a vigorous, destructive scratch.
When a bat colony moves as a group, the combined sound of dozens or even hundreds of these small creatures crawling can be amplified by the attic’s structure. Bats also create rustling noises when they maneuver through loose-fill insulation or when they flutter their wings near surfaces while landing or taking off. Because they are not built for running like a squirrel, their movements are typically awkward and slow on flat surfaces, which results in a distinct, less heavy sound profile. The noises are often concentrated near entry points or the tight crevices where the bats settle to rest.
Distinguishing Bat Noises from Other Pests
Identifying the precise source of attic noise depends heavily on the timing and character of the sound. Bats are crepuscular and nocturnal, meaning their activity is concentrated right around sunset when they exit to feed and just before sunrise when they return to the roost. If the scratching is heard most intensely during these twilight hours, bats are the most likely cause. This timing contrasts sharply with diurnal animals like squirrels, whose activity is loudest during the day, typically from sunup to sundown.
The nature of the sound itself provides another strong clue for identification. Bat sounds are usually light, high-pitched, and include chirping, squeaking, and a rapid, fluttery scratching or rustling. This differs from the heavy thumping or shuffling sounds produced by larger animals like raccoons. Rodents such as mice and rats create a faster pitter-patter noise, often including a distinct gnawing or chewing sound. The light, scuttling noise of a bat often remains localized to a specific area, such as a wall void, rather than traversing the entire ceiling quickly like a scurrying rodent.
Next Steps Addressing a Bat Presence
If you suspect bats are living in your attic, it is important to know that they are federally and state-protected species, and it is illegal to kill them. The only acceptable method for removal is humane exclusion, which involves allowing the bats to leave but preventing them from re-entering the structure. This process utilizes specialized one-way exclusion devices, such as bat cones or netting, which are installed over the primary entry points. These devices function like a one-way door, permitting the bats to fly out at dusk but physically blocking their return.
Timing the exclusion is critical due to the bat maternity season, which typically runs from late spring through late summer (May through August). During this period, flightless young, known as pups, are present in the roost and would be trapped inside to die if the entry points were sealed. A professional must wait until the pups are old enough to fly on their own, usually by late August, before installing exclusion devices. Because of the legal requirements and the complexity of locating entry points, it is recommended to consult a wildlife control professional specializing in bat exclusion.