HARRISBURG -- The Pennsylvania Game Commission is advising residents that August and early September can be a troubling month for homeowners with older houses, window air-conditioners, or dusk-to-dawn outdoors lighting, because their homes are more prone to be entered by a bat.
Twice over the past three years, Joe Kosack, a Game Commission wildlife education specialist, and his wife have awakened to a small brown bat flying in a circular pattern in their home. And this spring, Kosack dutifully did all he could to bat-proof his house, including sealing some suspicious weak spots in gable vent screening, inspecting soffit for unwanted passages and plugging the gaps around windows created between the sliding windows when he placed an air-conditioner in the window earlier this year. He assured his wife the house was bat-proof. But last Saturday night, a couple of little brown bats took exception to his claim.
"My wife heard light scratching at the window and alerted me to it, but I blew it off telling her it was rain or the air conditioner making noise," Kosack said. "She woke me repeatedly and even went over to window to listen. But I didn't budge and she didn't turn on the light to see what was going on. Both were big mistakes!
"At 5 o'clock Sunday morning, my wife woke me one last time and told me that we weren't alone. As she turned on the nightstand light, we were greeted by two bats flying overhead, sometimes a foot or two above our heads! She wasn't happy, and she told me repeatedly."
Kosack slipped out of the room grabbed a couple fine-meshed fishing nets and after about 10 minutes, he netted both bats and eventually released them outside. Removing the air-conditioner from the window - providing the bats an escape outlet - also would have worked, but it was screwed into the sill and would have taken some work to get out.
In this instance, the bats accessed the room by pushing through the foam insert - provided by the air conditioner manufacturer - placed between the windowpanes of the sliding window. Kosack suspects the bats went in-between the windows when the air conditioner was off. When it was turned on later, the bats opted to move upward, away from the humming appliance and into the house's living quarters. It took them several hours to work their way through the foam, but they did eventually.
"Regardless of how outdoors-oriented you are, the sight of a bat free-flying in your house will definitely quicken your pulse, partly because it's so unnatural, and partly because you promptly recognize that getting it outside isn't going to be easy," Kosack said. "The idea is to let the bat settle down, and that takes a few minutes. But it's not easy to be patient when a bat is circling your bedroom or den.
"In the time I spent apprehending my intruders, not once did I feel threatened. They were not aggressive; nor did they get real defensive when cornered. But they weren't happy about being contained in the net, and because of that, it's important to release them as quickly as possible to ensure these fragile mammals don't injure themselves trying to get away."
Each summer - with activity peaking in August - many Pennsylvania homeowners have closer-than-desired encounters with bats - mostly little browns and big browns. They are two of Pennsylvania's most common bats. Most often, the bats are youngsters, occasionally called "pups," that access the living quarters of homes while exploring, or after becoming disoriented while poking around in the nooks and crannies of a house. They either access the home from the outside, or from an established roost directly beneath the house's roof.
"Little browns and big browns set up nursery colonies in homes and barns throughout the state each spring," noted Game Commission biologist Lisa Williams, who authored Penn State University's A Homeowner's Guide to Northeastern Bats and Bat Problems. "Often, homeowners are unaware that they share their house with a bat colony until a pup pops into the bedroom. Of course, not every home with a wayward bat has a colony in the attic. But a bat in the living space of a home is a good reminder to double-check your house for signs of a colony and for bat entry points.
"By August, bat pups are as big as their parents and as the colony becomes more cramped, the young bats begin looking for less crowded places to roost. You can take advantage of this behavior by installing a bat box on your property. Bat boxes are most likely to be accepted by bats in August than any other time. Of course, bat boxes won't eliminate the chance of having a little or big brown bat drop in on you, but they may reduce the probability of it happening. In addition, having easy access to an alternative roost, like a bat box, may make the colony more willing to vacate your house."
The easiest - although not necessarily the quickest - way to alleviate a bat in the house is to contain the bat to one room by closing doors, and then open a window or two and wait for the bat to fly out. It's important to stay in the room so you can watch to make sure the bat has left. Stand quietly along a wall, away from the window, and wait for the bat to locate the open window. It's also a good idea to remove any pets and children from the room the bat is contained in; the more excitement in that room, the longer it will take the bat to settle down and concentrate on finding an exit.
If a bat won't leave, or you're unwilling to wait the bat out, your next best option is to perform a catch-and-release. This approach requires waiting for the bat to alight on something and then covering it with a bowl, strainer or a small-meshed fishing net. If you use a bowl or strainer, you'll have to slip something stiff and flat - like cardboard - under the bowl after you place it over the bat.
When using a fishing net, it's important to wear leather gloves and use a net that has stiff, small-meshed netting. Bats caught in nets with a soft, nylon mesh tend to further entrap themselves in the meshing. Usually the only way to free them then is by cutting the net. Once the bat drops to the bottom of the net, twist the netting above it, to contain it until you release it outdoors.
Whether using the window method, or catch-and-release, homeowners are advised not to chase after the bat.
"If you try to persuade the bat to leave or attempt to corner it, it likely will continue to fly," Williams noted. "Remember, the bat pup is probably as frantic as you are. It's also a bad idea to try catching a bat while it's flying, because the chances of injuring the bat or coming in direct contact with it are greater. The best bet is to stand quietly away from the center of the room and wait. Eventually the bat will head to the window or come to rest on something. Move slowly and quietly toward the resting bat to capture it.
"Bats are important members of Pennsylvania's wildlife community and are very beneficial to Pennsylvanians. One little brown bat can eat thousands of mosquitoes and other small-bodied insects each night. Big brown bats prey largely on agricultural pests, while our forest-dwelling bats help maintain forest health by devouring forest pests. The free pest control that bats provide should be more than enough reason to treat bats with care and respect."
In situations where a bat is present in the home and the possibility that someone has been bitten cannot be ruled out - for instance, a bat is found in a bedroom with a sleeping child - then the bat should be retained and tested for rabies. If that is not possible, the Pennsylvania Department of Health recommends that post-exposure treatment - rabies shots - should be seriously considered. If there is any chance that someone has been bitten or scratched, then the Department of Health recommends a physician be consulted and the local health department notified. Your physician should determine whether rabies shots are needed.
"In instances where you awake to see a bat - particularly if it's in your bedding - it's best to play it safe and consult a physician," Williams said. "Although most bat bites occur when someone attempts to pick up a bat barehanded, bites also occur when a sleeping person rolls onto a bat that has crawled into their bedding. Any bat found in a bed should be captured, killed without damaging the head, and tested for rabies.
"A bat in the air is generally a healthy bat, because bats stricken with rabies usually become crawlers; they don't have the strength and coordination to fly. But it's always a good idea to use gloves whenever attempting to capture or handle bats. It decreases tremendously the chances of being bitten."
For more information on bats, please consider consulting PSU's A Homeowner's Guide to Northeastern Bats and Bat Problems at http://pubs.cas.psu.edu/FreePubs/pdfs/uh081.pdf and the Pennsylvania Department of Health's Bat Rabies Fact Sheet, which is published at http://www.dsf.health.state.pa.us/health/CWP/view.asp?A=171&QUESTION_ID=230310.
