With their prolific ability to control insect pests, bats make good neighbors. As houseguests, though, the diminutive nocturnal predators quickly wear out their welcome.
That's what happened at Maple Hill United Methodist Church on Ridge Road in Brady Township, where, for 25 years, a breeding colony of about 3,000 Little Brown Bats (Myotis lucifugus) has caused a slew of problems, including showers of bat droppings whenever the church bell is rung and foul odors. The church congregation finally had enough and opted to evict the bats by sealing the opening through which the tiny mammals enter the structure and by installing new siding.
To offer a housing alternative, and to keep thousands of ousted bats from roosting in neighboring residences, the state Game Commission, Pennsylvania College of Technology and Lowe's have joined forces to construct a "bat condo" capable of holding 6,000 adult Little Brown Bats and 6,000 of their offspring. The condo is just the third of its kind to be built in Pennsylvania, said Donald Nibert, assistant professor of forestry at the College and coordinator of construction for the ambitious project.
"A great deal of labor is involved in the construction," Nibert said. "I can understand why there are only two others in the state. There are 86 sheets of plywood inside the condo forming baffles, which must be scraped on both sides so the bats can find footholds."
The Game Commission supplied the materials, purchased at cost from the Lowe's store in Montoursville, and approximately 75 Forest Technology students from the College have provided the labor to build the 8-foot-by-8-foot structure, which will be placed on 10-foot-tall, 6-inch-by-6-inch treated-wood posts in the first week of May.
The condo, which weighs nearly 2 tons, will be positioned 150 yards from the church on a concrete base, 30 yards from tree cover and close to water. A black roof retains heat, and the condo is sealed on the sides to prevent heat loss, since bats prefer warm sites for their nursery colonies. Total costs for the condo, $1,500, would have been $5,000 or more if the full price had been paid for the materials and labor costs had been added, Nibert noted.
"This is a cooperative effort from all three parties," he said.
The hope is the bats will take up residence in the condo and continue to provide the vital service at which they excel. Bats are the only major predator of night-flying insects.
According to the Penn State Cooperative Extension Office publication "A Homeowner's Guide to Northeastern Bats and Bat Problems," a single bat can consume 500 insects in one hour, or nearly 3,000 per night. A colony of just 100 Little Brown Bats, the most abundant species here, can consume a quarter-million mosquitoes and other small insects each evening.
According to the Game Commission publication "Bats Around the Home," most Pennsylvania bats settle into their winter quarters (usually caves or abandoned mines) by the end of October. They hibernate until spring, when the females return to the sites where they have established maternity colonies. Their young fledge by the end of July and begin leaving the roost by late August.