Rutgers Bat Distribution Program

Bats are often thought of as nuisance animals because they are commonly found roosting in manmade structures where they can produce large piles of guano (bat feces), get caught in living spaces, and pose a rabies risk. However, bats provide an essential ecosystem service by consuming night-flying insect species, including mosquitoes and agricultural pests. When homeowners perform a bat exclusion, which prevents bats from entering back into their home or other manmade structure, the evicted bats are forced to find new suitable roosting habitat. The Rutgers Wildlife Conservationand Management Program founded the Bat House Distribution Program in 2012, which provides free bat houses to property owners who are getting an exclusion performed on their property, to provide alternate roosting habitat for evicted bats. If property owners are not performing an exclusion but still want to install a bat house on their property, we sell and install bat houses for a reasonable fee. Since 2012, we have installed over 180 bat houses throughout New Jersey on residential properties, farms, farmer’s markets, churches, commercial properties, and a historic cemetery. Learn more about bat house installation guidelines, and contact us for pricing and availability.

 

Bat Conservation

Bats are some of the most misunderstood creatures on Earth. While many ancient cultures considered bats symbols of good health and fortune, the majority of popular myths associate bats with death and disease. In reality, bats are extremely intelligent, adaptive animals that provide many important benefits to humankind, most notably as voracious insect-eaters. Bats can eat over 100% of their weight in insects each night (that’s over 3,000 insects!), and because of their healthy appetites, have been valued at an estimated $22 billion per year to America’s agricultural industry.

Bats are unique in that they can be considered both as beneficial and nuisance animals, depending on the situation. Many people regard bats as pests because they can inhabit manmade structures and can pose a rabies risk. However, bats are nonaggressive animals that very rarely interact negatively with humans. Understanding the behavior and habitat requirements of bats can help to minimize conflicts between these valuable species and humans.

Bats are under threat from several anthropogenic factors, including construction of wind turbines, human disturbance, persecution, pesticides, and habitat destruction. White Nose Syndrome, a fungal disease recentlyintroduced to North America, is of most concern, having killed millions of bats since 2006.

2. Got Bats? Bats in Buildings

 

Why are bats roosting in my building?

Bats are loosely divided into two groups—tree bats and cavity-roosting bats. Cavity-roosting species generally live in groups and enjoy huddling together in warm, dark, and predator-free spaces. This is especially important for females, who congregate together in the spring and summer in “maternity colonies,” where they give birth to and raise their pups. Bats prefer roosting in dead trees, but forestry practices have largely eliminated these “hazard” trees, forcing bats to find other alternatives. Some species have adapted to roosting in man-made structures, particularly in barns lofts, attics, and eaves, which stay warm enough at night to protect fur-less pups from the cold spring nights. Some bats may also hibernate in buildings. The most common species found in man-made structures are big brown bats (Eptesicus fuscus).

Do the Bats Roosting in My House Pose Any Risk?

A small number of bats roosting in your house or barn are not likely to cause any problem or health concern for you or your family. In fact, they are conveniently removing insect pests from your backyard every night in the spring and summer!

Where large quantities of bat droppings (called guano) have piled up for several years and are located in a confined space, there is a potential human risk of Histoplasmosis infection. Histoplasmosis is caused by inhaling the spores of the Histoplasma fungus, which is found in soil and then enriched by bird or bat droppings. The infection may be asymptomatic or cause flu-like symptoms, but it rarely requires treatment. Histoplasmosis is only a threat when the guano is disturbed and spores are released into the air. These conditions are usually only found in caves or abandoned buildings. Bats roosting inside a home typically do not occur in numbers great enough to produce such quantities of guano. Scattered or small piles of droppings pose no harm and can be swept up with no risk to human health.

For information concerning rabies, see Bats and Rabies.

Should I Evict Bats from my Home?

The decision to evict bats that are roosting in a manmade structure should be an informed one. In some cases, bats are solely using the exterior of the structure and cannot access the inside. Bats may be roosting beneath the flashing of the chimney, in between the slats of shutters, or inside the soffit or overhang. Without access to the interior of the house, bats cannot enter the living space. Bats that do access the interior of the structure usually roost in the attic or chimney and may occasionally enter the living space.

How Do I Evict Bats from My Home?

Evicting bats from your home involves three general steps, inspecting the exterior of the house for all crevices that may be used as access points; sealing all holes except the main access point used by the bats, and installing a one-way door, which allows the bats to exit but prevents them from returning. Once all the bats have left the roost (usually after a week), the main access point can be sealed. Bat exclusions can be done yourself, but they are more commonly performed by professional bat excluders.

All bats in NJ are protected under state law, and it is illegal to harm, harass, or kill them. Therefore, all bat exclusions must be conducted following the Nuisance Wildlife Control Guidelines for Bats (48k PDF). Most importantly, bat exclusions may only be performed during April 1–April 30 and after August 1. If bats are known to be hibernating in a building, then an exclusion can only occur during the month of April. Exclusion guidelines are in place to prevent bats, particularly non-flying pups, from being trapped inside structures.

What Happens to Evicted Bats?

Bats evicted from homes (even during the “safe dates” described above) face some challenges. Nightly April temperatures are typically <50°F with little or no insect food items. The stress caused by a lack of food, coupled with the need to search for a new roost site and the absence of a warm refuge, may cause death to adult bats or unborn fetuses. In addition, they may attempt to access a neighboring home, displacing (not resolving) the problem. Finally, bats are extremely site-fidelic and will return to former roost sites annually. Because of this, professional bat excluders may not guarantee the work for more than a couple years.

What is a Long-term Solution?

Installing a bat house near the original roost prior to eviction can provide immediate refuge to evicted bats, reducing stress and increasing survival. If evicted bats adopt the bat house, the bat-human conflict may be resolved for the long term.

If you have bats and are considering a bat exclusion, the Rutgers Wildlife Conservation and Management Program can provide and install a bat house on your property through our Bat House Distribution Program (PDF). In exchange for this service, we ask that you enroll in our Project: Batwatch (PDF) program so that we can evaluate the success of this initiative to provide long-term solutions to bat-human conflicts.

For further guidance on bats in buildings or to report a bat colony on your property, please fill out our online reporting form.

5. Bats and Rabies

What is Rabies?

Rabies is a fatal viral infection that is spread by the saliva of infected animals, generally through a bite.

How Common is Bat Rabies?

Less than 1% of all bats carry rabies, and bat bites are very rare. From 1995 – 2009, an average of 2 people per year in the U.S. died from contact with rabid bats. In contrast, the majority of the estimated 59,000 rabies deaths worldwide each year are caused by dog bites. Over 99% of human deaths caused by rabies occur in Asia, Africa, and South America.

How Can I Get Rabies from a Bat?

A potential rabies exposure from a bat can only occur through a bite. A bat that is lying on the ground is much more likely to be infected and may bite if handled. According to the Center for Disease Control and the NJ Department of Health, a bat that is found in a house where people are sleeping should be caught and tested for rabies. However, it is highly unlikely that a person could unknowingly be bitten by a bat. Exceptions include young children, the mentally impaired, or those under the influence of alcohol. Therefore, under most circumstances, steps should be taken to allow the bat to freely exit the house.

Do Bats with Rabies Act Abnormally?

Rabid bats do not become overly aggressive or attack humans. A bat with rabies will get sick, and may show abnormal behaviors, such as daytime flight, paralysis, or an inability to fly. Grounded bats may be more likely to have rabies than bats that can fly, so it is important to NEVER handle any bat without proper protection.

I Came in Contact with a Bat… Was I Exposed to Rabies?

Contact with a bat is defined as a bite, scratch, or other physical contact with a bat. If contact has occurred, immediately clean the affected area with soap and water. Contact your medical provider to receive post-exposure rabies vaccines, and let the local health authority know about the bite.