Bats are generally beneficial creatures that play an important part in many ecosystems, primarily by consuming insects, pollinating plants, and dispersing seeds. Despite their ecological contributions, concerns can arise when bats enter human living spaces, especially regarding potential bites that may go unnoticed during sleep.
Understanding Bat Behavior
Bats are not naturally aggressive towards humans and typically avoid contact. A bat will primarily bite in self-defense if it feels threatened, such as when it is handled or cornered. If a bat is ill, particularly with rabies, its behavior can change, making it disoriented and more prone to biting without provocation. Less than 1% of bats in the wild are estimated to be infected with the rabies virus. Even among bats submitted for testing, only about 3-6% are found to be rabies-positive.
How Bites Happen During Sleep
Bat bites can be very small, often resembling tiny pinpricks, and may not leave a noticeable mark. A bat might enter a home through small openings like an open window, an unscreened chimney, or gaps around utility vents. Once inside, a disoriented bat might come into contact with a sleeping person. Due to their small teeth and the shallow nature of the wound, the bite might not be painful enough to wake the person. Therefore, if a bat is found in a room with a sleeping person, direct contact and a potential bite must be assumed, even if no visible marks are present.
The Rabies Risk
Rabies is a severe viral disease that affects the nervous system and is almost always fatal once symptoms appear. The virus is primarily transmitted through the saliva of an infected animal, typically via a bite or scratch. While rare, transmission can also occur if infected saliva comes into contact with open wounds or mucous membranes like the eyes, nose, or mouth. Although only a small fraction of bats carry rabies, they are the main source of human rabies cases in the United States. The severity of rabies highlights why any potential exposure, especially an unconfirmed bite during sleep, must be taken seriously and promptly addressed.
Immediate Steps After a Bat Encounter
If a bat is found in a room with a sleeping person, an unattended child, or anyone unable to confirm that they were not bitten, it is important to capture the bat safely for rabies testing. Do not release the bat, as testing is the only way to confirm if it carries rabies. Wear thick gloves when attempting to contain the bat, using a plastic tub or similar container to trap it, then slide a piece of cardboard underneath. Immediately after containment, contact local public health officials or a healthcare provider for guidance. They will assess the situation and likely recommend post-exposure prophylaxis (PEP), which typically involves a dose of rabies immunoglobulin and a series of rabies vaccines administered over a few weeks, highly effective in preventing the disease.
Keeping Bats Out of Your Home
Preventing bats from entering your home involves sealing potential entry points. Bats can squeeze through openings as small as 0.5 to 0.75 inches. Inspect your home’s exterior for cracks, gaps, and loose siding, especially around windows, doors, and utility penetrations. Ensure that screens on windows and doors are intact and that chimneys are capped. Sealing these gaps with caulk, weather stripping, or hardware cloth can significantly reduce the likelihood of bats entering.
If bats are already roosting in an attic or wall, it is recommended to consult wildlife control professionals for humane exclusion. They can install one-way devices that allow bats to exit but prevent re-entry, often timed to avoid trapping flightless young.