For a few nights, Stepfanie Malone woke to soft fluttering noises in her third-floor Aberdeen apartment, but thought little of it. When she left the lights on one night, she discovered that a small brown bat was the source of the disturbances in the dark. Maintenance workers trapped the animal the next day.
"It frightened me, but it didn't bite me," she said.
That was the first and last bat encounter for Malone, and since she was not bitten or scratched, she was not in any danger of contracting rabies.
But more than 30 others in the Harford County city — six in her Perrywood Gardens complex — have not been so fortunate. The county Health Department has referred them for a series of five vaccinations to prevent the deadly virus.
A bite from the tiny creature or even contact with its saliva, possibly through a scratch or cut, could spell danger. Health officials said they are not taking any chances, even though fewer than 1 percent of bats are carriers.
"Only a small number of bats have rabies," said state public health veterinarian Dr. Katherine Feldman. "But the risk is real. Most cases of rabies in the U.S. are from bats. If you have been exposed, you must seek treatment."
In 2010, the Maryland Department of Health and Mental Hygiene handled 362 cases of animals that tested positive for rabies, 44 of which were bats. About 900 people were treated with the vaccine to prevent rabies, a number that is fairly consistent each year, said Dr. Katherine Feldman, state public health veterinarian.
While bats are important to the ecosystem, "they should not be sharing living spaces with people," Feldman said.
The Harford County Health Department reported last week "significant bat colonizations" and numerous sightings within apartments at the Cranberry Run and Perrywood Gardens apartments, which are home to a few hundred people. The apartments' managers have declined to comment, but they are working with licensed wildlife control operators, health officials said, to exclude the critters from their roosts, which are mostly in the attics of the three-story buildings.
State health department officials say bat colonization in apartments and other buildings is not uncommon this time of year, when the animals are with their young. Local health departments get involved to ensure management companies hire licensed wildlife operators to exclude the bats.
Tenants have reported bat sightings in several different buildings, but most have not been exposed, officials said.
In Harford, health officers are canvassing the neighborhoods, calling homes and putting fliers on tenants' doors. They are holding community meetings in an effort to educate the public and to locate anyone who might have been bitten by a bat or exposed to its saliva. Those people must seek immediate treatment, officials said.
"There is a heightened risk of rabies exposure," said Bill Wiseman, Harford's health department spokesman. "So, we are particularly checking homeowners who have reported sightings."
Health workers are also contacting tenants who have moved from the apartments as far back as Jan. 1.
Workers are trying to bat-proof the aging buildings by screening and plugging cracks — as small as a quarter of an inch — that the animals use as entry points. The goal is to make it impossible for the critters to return to their roosts in the buildings, each with several apartments, and to encourage colonization elsewhere, preferably in the wild.
Bats' appetite for insects, especially mosquitoes, makes the flying mammals valuable to the ecosystem. Simply being around them poses no danger, but direct contact can, said Susan Kelly, Harford's health officer.
"We have seen an abundance of bats this year, and that's a good thing," she said. "We just don't want them colonizing apartment complexes."
The department has not received reports of sightings other than from the tenants at the apartments but has asked residents to stay on the alert for colonies and to report them.
Residents who have been bitten or scratched should immediately wash the affected area and contact the department. Capturing the bat safely, if at all possible, will assist officials in determining the danger, particularly if a bite is involved.
Jonathan McKnight, a biologist with the Maryland Department of Natural Resources, said bats will leave the apartments naturally for winter quarters by early September.