Bats are flying mammals that play a part in various ecosystems, often consuming insects, which helps control pest populations. Despite their ecological value, many people wonder about the potential for bats to bite humans. While such encounters are not common, understanding the circumstances that lead to them and the associated risks is important for public safety.
When and Why Bats Bite
Bats generally do not seek to bite humans; their aggression is almost always a defensive reaction. A bat might bite if it feels threatened, trapped, or is handled. If cornered or picked up, a bat’s natural instinct is to defend itself through biting or scratching.
Unprovoked attacks from bats are rare. However, bats that are sick, particularly with rabies, may behave unpredictably and bite without apparent provocation. Bat teeth are quite small, and their bites can be tiny, sometimes leaving marks that are difficult to see or that disappear quickly.
The Primary Risk: Rabies Transmission
The potential transmission of rabies is the main public health concern linked to bat bites. Rabies is a severe viral disease that affects the central 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, or if saliva comes into contact with open wounds or mucous membranes like the eyes, nose, or mouth.
While rabies is present in bat populations, most bats do not carry the virus. Among bats randomly sampled in the wild, less than one percent are typically found to be rabid. However, this percentage can be higher, around six percent, for bats submitted for testing, often because they exhibited unusual behaviors such as being active during the day, struggling to fly, or being easily approached. In regions like the Americas, where dog-mediated rabies is largely controlled, bat bites have become the most common source of human rabies infections.
Immediate Steps After a Bat Encounter
If a bat bite or scratch occurs, or if there’s any direct contact with a bat’s saliva, immediate action is necessary. Thoroughly wash the affected area with soap and water for several minutes. Then, seek medical attention immediately.
Even if no obvious bite marks are visible, medical evaluation is recommended if a bat was present in a room with a sleeping person, an unattended child, or an individual unable to confirm contact. Post-exposure prophylaxis (PEP), which involves a series of vaccinations and sometimes immune globulin, is highly effective in preventing rabies if administered promptly. If possible, the bat should be safely captured for rabies testing by animal control or a public health agency, without damaging its head, as this can help determine if PEP is necessary.
Preventing Future Bat Encounters
Avoid handling bats with bare hands to reduce the risk of encounters and potential bites. If a bat is found indoors, contact local animal control or a wildlife professional for safe removal.
Secure your home against bat entry. Bats can fit through surprisingly small openings, sometimes as narrow as half an inch. Inspect and seal any gaps around windows, doors, and utility lines, and ensure that screens and chimney caps are intact. Trimming trees and other vegetation away from the house can also eliminate potential launch points bats might use to access your home. Educate children and pets to avoid touching or approaching bats.