Bats are interesting mammals that have intrigued humans for hundreds of years. There are 11 species of bats found throughout Ohio. All of these species are insectivorous (feed on insects) and are nocturnal (active at night) or crepuscular (most active at dusk and dawn). Bats are beneficial because they feed on and help to control many agricultural pests. Depending on the species, some bats such as the hoary bat, the red bat and the silver-haired bat, migrate south in the cold winter months when insects are rare in Ohio. Other bats hibernate during the winter. In Ohio, bats typically hibernate from late October to early April in caves, abandoned mines, cracks in large rock outcroppings or attics and buildings. Bats can carry diseases that can spread to people or animals.
Bat-related diseases of concern in Ohio:
Histoplasmosis is caused by the fungus, Histoplasma capsulatum. Histoplasma can be found in soil throughout the Ohio Valley, but it can also be shed in large numbers in bat droppings. People get histoplasmosis when they inhale spores that have become airborne. Symptoms of infection range from mild flu-like symptoms to serious lung infections. The young, the elderly, those with pre-existing lung conditions and the immunocompromised are particularly at risk for severe infections. Additional information is available on protecting workers at risk for histoplasmosis.
Rabies virus can infect any species of mammal. It causes encephalitis and is almost always fatal once symptoms develop. It is spread when a person or animal is bitten by an infected animal or, less commonly, when saliva from an infected animal gets into an open wound or onto a mucous membrane. Most of the human rabies cases acquired within the United States during the past 20 years were due to bat strains of rabies. Since a bat bite is very small and may go undetected, the history of any potential bat contact should be carefully evaluated to determine the potential for exposure. All exposures should be reported to the local health department and the bat tested for rabies if it is available. It is also important to vaccinate your pets against rabies. Many of the bats submitted to the Ohio Department of Health's Bureau of Public Health Laboratory for testing exposed at least one family pet. Even indoor cats are at risk of exposure to a potentially rabid bat. If you want information on potential exposure criteria, safely capturing a bat for testing, or general information, please review the information sources below.
Last updated: 03/06/2015
Zoonotic Disease Program