When bats fly near a home at dusk, it indicates the property is within their nightly foraging territory. These insectivores are engaged in their natural nocturnal routine of hunting and scouting, not necessarily seeking to enter the living space. Understanding the difference between a bat simply passing by and one attempting to establish a roost is key to managing their presence. Their presence is primarily driven by the availability of food, water, and suitable shelter for daytime rest.
Understanding the Reasons for Their Presence
The most common reason bats circle a residential area is to hunt insects, which are often drawn to outdoor lighting or landscapes near a home. A single bat can consume thousands of mosquito-sized insects in a single night, making their presence an effective form of natural pest control. Their foraging flight patterns, characterized by rapid, erratic movements, are a result of using echolocation to pinpoint and capture tiny flying prey in the dark.
Foraging behavior differs from scouting for a roost, which involves a more deliberate flight path closer to the structure. Bats seek warm, dark, and secure locations to spend the day, and buildings offer crevices that mimic natural roosting sites like tree hollows or caves. They are attracted to the heat escaping from homes, often locating small gaps around fascia boards, chimneys, or attic vents. Repeated flight directly to and from a specific point on the structure indicates they may be using that opening as an established entrance and exit point.
Immediate Safety and Health Protocols
While most bats are healthy and pose no threat, the main health concern associated with their presence is the transmission of rabies. Rabies is nearly 100% fatal once symptoms appear, though the incidence in the wild bat population is estimated to be less than one percent. Because their teeth are tiny, a bat bite or scratch can go unnoticed, requiring caution regarding any direct contact.
Potential exposure is assumed if a bat is found in a room with a sleeping person, an unattended child, or an impaired individual. In these scenarios, the bat must be safely captured for laboratory testing; a negative result eliminates the need for post-exposure prophylaxis (PEP). Never touch a bat with bare hands, and immediately contact local health authorities for guidance on testing and medical steps.
A second health consideration arises when a colony establishes a long-term roost inside a structure, leading to a buildup of droppings known as guano. Large accumulations of guano can foster the growth of the fungus Histoplasma capsulatum. If these droppings are disturbed, the airborne fungal spores may cause histoplasmosis, a respiratory infection with flu-like symptoms. Cleanup of substantial guano deposits should only be performed by professionals using specialized protective equipment.
Specific Steps If a Bat Enters the Living Space
If a bat accidentally enters the occupied living space of a home, the goal is safe and humane removal without contact. First, confine the bat to one room by closing all interior doors and sealing the space beneath them with a towel. Turn off the lights, as the bat is likely disoriented and will look for a source of natural light to exit.
Open an exterior door or window to the outside and stand quietly or leave the room entirely, allowing the bat a clear path to escape. The bat should exit within a few minutes once it locates the open air. If the bat lands and must be captured for testing due to potential exposure, put on thick leather gloves. Place a coffee can or similar container over the bat, then slowly slide stiff cardboard between the wall and the container to trap the animal.
Humane Exclusion and Prevention Methods
Long-term prevention focuses on a process called exclusion, which involves sealing all entry points after the bats have been safely evicted. Bats can squeeze through openings as small as a quarter-inch, so a thorough inspection of the roofline, chimney, vents, and siding gaps is necessary to locate all potential access points. Materials like caulk, steel wool, or fine-mesh screening should be used to permanently seal every opening except for the main exit point.
Because bats are protected by law in many regions, eviction must be done humanely using one-way exclusion devices. These devices are installed over the main entry point and consist of a tube or plastic netting that hangs down, allowing bats to drop out at dusk but preventing them from climbing back in. Exclusion must be timed outside of the bat maternity season (mid-spring through August) to avoid trapping flightless young inside the structure. Sealing the home during this period would starve the pups, leading to odor issues and violating wildlife protection laws.