Wednesday, June 8, 2005

 

What to do when bats are discovered in your home

It's that time of the year again when many Georgians discover small, secretive visitors sharing their homes. These visitors prefer to be left alone in the attic or other warm, confined space during the day, and then emerge at night to earn their keep by consuming vast quantities of flying insects. Despite their skills at controlling insects, bats are still not always welcomed by their human landlords. Bats can present problems, but the fact is that much of the fear they instill is excessive, unjustified, and based largely upon misinformation.

One persistent falsehood is that bats are protected by laws such as the federal Endangered Species Act and can't be legally removed from an attic. State and federal biologists say that this just is not so, and that nuisance problems with bats can be resolved safely.

"Many people despise bats because they perceive these animals to be dangerous carriers of disease," said Jim Ozier, a senior wildlife biologist for the Georgia Department of Natural Resources’ Wildlife Resources Division. "While bats can transmit rabies to people, such incidences are extremely rare. Most bat bites are a result of an obviously sick bat being handled."

As with most wildlife species in Georgia, bats are protected by state law. It is illegal to intentionally capture, kill, or harm any of the sixteen species found in the state. Most species roost in caves and trees, but a few species have adapted to using human structures for shelter. The Georgia Department of Natural Resources allows removal of these bat colonies on a case-by-case basis, usually with little expense to the homeowner and no harm to the bats.

As for federal law, Sandy Tucker, U.S. Fish and Wildlife Service Field Supervisor, said that the Endangered Species Act does not apply in most situations involving humans and bats in Georgia. Tucker, head of the USFWS Georgia Ecological Services office, said that only two bat species found in Georgia are protected under the Endangered Species Act, the gray bat and Indiana bat. These live in either cave-like or upland forest habitats in the northwestern part of Georgia, and neither favor human dwellings.

Even if a federally protected bat species were involved, Tucker said; "There's flexibility under the Endangered Species Act that gives choices when conflicts occur between human health and listed species."

As for removing bat colonies from homes, the three species usually found in human structures are the evening bat, big brown or the Mexican free-tailed bat. Their colonies can be excluded from structures by sealing openings and using temporary excluder devices that allow bats to fly out in the evening to feed, but prevent their return to the attic.

Excluders can be built by tacking a sheet of plastic or netting across the top of the entrance hole, down along each side two feet past the hole and then left unattached at the bottom. In a few days when all the bats are gone, remove the excluder, and seal the hole. Many people install their own excluders, but a list of certified professionals can be obtained by contacting DNR's Special Permits Office at 770 761-3044.

The best time to install an excluder is during the spring prior to May 1st or in the fall after August 15th. During the summer, flightless infant bats might be present, and these would die once the adults are excluded. If bats are getting into someone's living space or otherwise presenting a health hazard, they can be excluded at any time.

In fact, Ozier said that people should act quickly if bats are discovered in a building where they are not wanted. "The longer the bats are allowed to use the site, the larger their numbers are likely to grow and the more guano that will be deposited inside."

Guano, or bat excrement, sometimes accumulates at a roost site and can cause structural damage to the building. Additionally, a fungus sometimes grows on the droppings. If large quantities of fungal spores are inhaled, a lung infection known as histoplasmosis can result.

Homeowners should also seek technical advice from qualified sources before attempting to handle bat exclusions themselves. If they hire someone to do the job, they should make sure the person is qualified, permitted and aware of proper exclusion techniques.

Bats are undoubtedly one of the most under-appreciated animals that contribute to our diverse natural heritage. They are the only mammals that can truly fly, and though they somewhat resemble mice, they are not closely related to rodents and do not gnaw. The bats in Georgia aid humans by eating as much as half their weight each day in mosquitoes, beetles, moths and other insects. A single little brown bat can alone catch up to 1,200 insects in just one hour.

Many people install specially designed roosting structures, known as bat boxes, which give bats a home away from human homes. If the bats find the roost box suitable, they remain in the area to continue their insect assault.

"Bats are a valued and economically important component of our natural heritage. We should strive to conserve habitat and develop a greater appreciation for bats and other wildlife," concluded Ozier. "However, there are times when bats seek shelter in places where they cannot be tolerated. These situations should be handled sensibly and responsibly to prevent harm to the people and the bats involved."