The McHenry County Department of Health said Monday that bat encounters in the county are on the rise.

Health department spokesperson Nick Kubiak said “we don’t have a definitive reason for the increase in bat encounters, but it could be due to several factors: increased public awareness and education by the MCDH about bats and the rabies virus, leading to more people calling for assistance; seasonal activity, as bats are more active in late summer through early fall; and local law enforcement advising people to report bat encounters to McHenry County Animal Control.”

The department posted on social media Monday encouraging residents to know the risks of bats and rabies and know how to stay safe.

The department said in the post that rabies is “a viral disease that is most often transmitted through a bite of a rabid animal. Rabies infection results in progressive inflammation of the brain that is fatal if left untreated. It is preventable with prompt medical care.”

Not all bats are rabid, but contact with rabid bats is the leading cause of rabies deaths for humans in America, the department said.

A bite from a bat can expose a person to the virus, even if they don’t notice the bite because of bats’ small teeth. Potential exposures also include waking up to find a bat in the room or a bat being in the same room as a child, a person with cognitive disabilities or someone under the influence of drugs or alcohol, according to the post.

People who think they may have been bitten or had close contact with a bat should call the health department communicable disease division at 815-334-4500. A registered nurse will ask questions to determine whether an exposure happened. If an exposure is confirmed, people will be referred to the nearest medical facility for post-exposure prophylaxis treatment. Treatment includes rabies immunoglobulin and a series of rabies vaccines, according to the post.

To help protect against bats getting inside, people should seal any exterior openings larger than ¼ inch, especially around screens, pipes, vents, chimneys, fireplaces and roofs. Windows should be screened, and screens should be in good repair. Unscreened windows and doors should stay closed, according to the post.

Those who find a bat in their residence should call McHenry County Animal Control at 815-459-6222. Residents should secure the space by closing doors and windows, placing a rolled towel under the door and keeping people and pets out of the room until they get further instructions.

People should not handle bats with their bare hands, and licensed Nuisance Wildlife Control Operators can help identify potential bat entry spots and provide bat exclusion services, according to the post.

Cats and dogs are required to be vaccinated against rabies in Illinois, but without immunization they can carry the disease, along with bats, raccoons, foxes and skunks, according to the post. Infected animals might foam at the mouth or have abnormal behavior, including aggression, paralysis or seizures.

Kubiak said the increase in bat encounters prompted the post. The number of reported bat exposures in July was down slightly from June, 22 compared to 23.

The department previously reported 17 potential human exposures to rabies in June, but the number has been revised upward since. The data is provisional, but the department notes that statistic may overestimate the number of people exposed to rabies because it includes people who might have received rabies post-exposure prophylaxis against public health recommendations. In May, the department reported 12 exposures.

The year-to-date total of rabies exposures stands at 75 as of the end of July.

A rabid bat was found at a home in Ringwood in May, which was the first rabid bat discovered in the county in 2025. No humans were exposed to the bat, health officials said at the time.

Kubiak said the health department hasn’t seen an increase in rabies cases in the county, but will “continue to monitor the situation closely to ensure public safety and respond promptly to any changes.”

For more information, call the health department communicable disease program at 815-334-4500 or visit the Illinois Department of Public Health rabies page at bit.ly/idph-rabies.