Fall is in the air — and so are bats. This is the time of year when Idaho’s only flying mammals migrate to warmer climates or to suitable roosts for hibernation. Sometimes during this migration, they make temporary “pit stops” and roost in places where people don’t typically see bats. Maybe a business owner finds a bat under an awning over a front entry, or a school may have bats on the side of the building, or a homeowner may find them hanging above a window. Usually these visits only last one or two days, and the bat is on its way again.
In recent weeks, a few stories involving bats and rabies in Idaho have been shared with the public, including cases in Pocatello, Bingham and Bonneville counties and in the Twin Falls area. Around five bats submitted to health departments in these areas tested positive for rabies.
Though the thought of contracting rabies — a fatal disease — is both unsettling and serious, there are some misconceptions about bats and rabies as well as facts that everyone should know.
Rabies in bats is uncommon.
- Prevalence of rabies in bats is half of a percent. That’s because when a bat contracts rabies, it dies. Bats do not “carry” rabies; that is, bats are not asymptomatic carriers of the disease.
- Most infected bats have the paralytic form of rabies rather than the furious form. What does that mean? It means that an infected bat will not usually exhibit signs of excited, hyperactive or overly aggressive behavior followed by a quick death. Bats are, by nature, gentle animals and only rarely act aggressively — even if infected with rabies.
- Rabies is a viral disease that is transmitted through the saliva or tissues from the nervous system of an infected mammal to another mammal, usually through a bite. You cannot contract rabies through bat blood, urine or guano or from touching a bat on its fur (although bats should never be handled with bare hands).
- So why do health departments often find a significantly higher rate of rabies in the bats they test? That is because the bats that are submitted for testing are often sick and were likely more easily captured because they are sick. Let’s look at that another way. People in a community who are seriously sick or injured are often admitted to the local hospital. You wouldn’t make the generalization that most humans in your town must be sick or injured just because most of the patients at the local hospital are.
- Bats are most active at night and even in the early morning hours, but that doesn’t mean that a bat flying around during the day is sick or rabid. Though a sick bat may be active during the day, healthy bats will also fly during daylight hours if they have been disturbed from their roost by a predator, weather or even a person. Bats are even known to use daylight hours to grab a drink of water or a quick bite to eat — their version of a “midnight” snack.
- The United States Centers for Disease Control and Prevention reported that a total of 25,799 bats were submitted in the United States for rabies testing in 2015, of which 1,704 (6.6 percent) were confirmed rabid. Compare this to other wild mammals. There were 12,359 raccoons submitted for rabies testing in 2015, of which 1,619 (13.1 percent) were confirmed positive. A total of 4,857 skunks were submitted for testing in 2015, of which 1,365 (28.1 percent) were positive, and a total of 1,732 foxes were tested for rabies, of which 325 (18.8 percent) were positive. What this shows is that animals besides bats can carry rabies, and that in spite of a much higher number of bats submitted for testing compared to other mammals, the frequency of rabid animals was far less for bats than for the other species. And remember, the incidence of rabies in wild bat populations is even lower than that of bats submitted to health departments for testing.
- According to the CDC, in this century, the number of human deaths in the United States attributed to rabies has declined from 100 or more annually to an average of two or three annually. The CDC attributes this decline to two programs. First, animal control and vaccination programs that began in the 1940s and oral rabies vaccination programs in the 2000s have eliminated domestic dogs as reservoirs of rabies in the United States. Second, effective human rabies vaccines and post-exposure treatments have been developed.
What to do if you encounter a bat?
- Though the frequency of rabies in bats is extremely low, it is important that if you encounter a bat, don’t touch it. In fact, you shouldn’t pick up or touch any wild animal.
- If you wish to remove a bat from an interior, it may be as simple as providing the bat an escape route by leaving a window or door open. If the bat is in a location you can reach, maybe even clinging to a wall or curtain, you can place a small box over the bat and then slide a piece of cardboard between the box and the wall to trap the bat in the box. Then the bat can be released. Never directly handle a bat, and even when trying this removal method, gloves should be worn. See Idaho Fish and Game’s short video that shows how to safely capture a bat and release it at https://bit.ly/2x7sYW5.
- Keep in mind that bats roosting on the outside of your house, especially this time of year, are just likely moving through the area and will leave within a day or two. Leave them alone, and they will leave you alone. If you see a bat crawling around on the ground and seemingly unable to fly, safely contain the bat (ensuring that no one handles the bat with bare hands) and call Idaho Fish and Game for help.
- If you suspect or know you have been bitten or scratched by a bat, collect the bat if you can for testing and be sure to contact your doctor to discuss post-exposure treatments. These treatment procedures are precautionary and prevent people from developing rabies if the virus has been passed to them.
- Pets may encounter bats and other wild animals in the outdoors or near your home. Always vaccinate your pets for rabies, including dogs, cats and horses.
- All bat species in Idaho are classified as Protected Nongame Species; however, that doesn’t mean you have to live with bats in your attic. If you have some unwanted “roommates,” give Fish and Game a call, and we can provide direction for their removal or exclusion or can recommend certified services that can be hired to do removals and exclusions of bats. Never try to remove bats from your home using lethal methods; humane exclusion and prevention is much more effective. Humane exclusions are best performed in the fall after bats have left your home for the winter.
Bats are extremely beneficial.
- There are 14 species of bats in Idaho, all of which eat insects. The Pallid Bat will even eat scorpions and other larger invertebrates. The Little Brown Bat can consume more than 1,000 mosquitoes in an hour. A pregnant bat can eat almost 100 percent of her body weight in one night.
- Bats are worth about $74 per acre to farmers because they eat agricultural insect pests. In Idaho alone, bats are worth an estimated $313 million annually to the agricultural industry.
- There are nectar-feeding bats in Arizona and California. The Century Plant (a type of agave) from which tequila is made relies on pollination by long-nosed bats.
- Guano produced by bats is an excellent organic fertilizer, and some countries export guano as a commodity.
For more information about bats and rabies, contact your nearest Idaho Fish and Game office, or check out any of the following websites: www.cdc.gov/rabies, www.batcon.org, www.batworld.org, and visit Idaho Fish and Game’s YouTube channel for great videos on bats and bat research happening in Idaho.
Jennifer Jackson is the regional communications manager for the Idaho Department of Fish and Game, southeast region.