CLARKSVILLE -- Stirring up billows of dust in the stifling heat, Heidi Hughes followed her flashlight beam around the attic of a 200-year-old farmhouse here last week in an effort to rescue a few of America's most misunderstood mammals.
The 44-year-old naturalist and co-founder of the American Bat Conservation Society was disappointed: All that was left of a small band of big brown bats was some dried-out corpses. Perhaps, she speculated, they were trapped and died when a heat wave raised temperatures in the stone attic, or they starved or were accidentally poisoned by eating insects killed with pesticides.
Even if some members of the colony of M. lucifugus survived, they were unlikely to return and rebuild.
"It's like a small city was wiped out," mourned Ms. Hughes.
But all was not lost. Ms. Hughes gently preached the gospel of bat conservation to homeowner Laura O'Keefe, 24, who discovered she had bats when two blundered into her upstairs hallway.
She and her husband, Eric, raced around chasing the creatures until they darted out a window. She called the Howard County animal control office, which referred her to the American Bat Conservation Society.
Bats, Ms. Hughes told Mrs. O'Keefe, don't deserve their reputation as sinister, diseased vermin that nip children and deliberately get tangled in people's hair. (It's a popular notion: Batman, after all, adopted his costume to frighten criminals).
Instead, she said, they are cuddly creatures, as harmless as butterflies, that consume vast quantities of annoying insects. "I don't think I've ever met a bat I didn't really like," Ms. Hughes said.
Mrs. O'Keefe, whose family lives on a 155-acre farm, was leery at first. But by the time Ms. Hughes prepared to leave, Mrs. O'Keefe said she was disappointed the colony was wiped out.
And because of Ms. Hughes' visit, she confided: "I'm a little less afraid of them."
Ms. Hughes, president of the Wild Bird in Rockville, and Dr. Thomas Valega, an administrator with the National Institutes of Health, founded the non-profit bat conservation group last year.
Working out of their Rockville bungalow, the couple leads twilight bat-watching hikes, publishes newsletters, and gives talks featuring their collection of live bats. They have helped mount more than 50 missions by "bat rescue squads."
They've built the society into what may be the nation's second most prominent bat education group, after the larger Bat Conservation International of Austin, Texas.
Dr. Valega and Ms. Hughes think that U.S. bat populations have declined drastically in recent years, due to the misuse of pesticides, predation by cats, disturbances during hibernation and the destruction of roost sites in mines and caves.
To get the public to care, bat advocates say, they must improve the creature's tarnished image. "Bats in this country have gotten bad press right from the get go," Dr. Valega said.
While some Asian cultures revere them as good luck symbols and British homeowners are forbidden to evict them, bats in America are routinely swatted with tennis rackets, poisoned, chased with brooms and bashed with rolled-up magazines.
Cave-dwelling bat colonies are trapped or evicted when mining firms seal up abandoned shafts. Cavers sometimes disturb other colonies during winter hibernation, causing them to squander precious body fat and, sometimes, to starve.
The ABC Society, meanwhile, preaches peaceful coexistence with the 42 species of American bats, including the 10 found in Maryland -- big brown bats, little brown bats, silver-haired bats, hoary bats, red bats, the Eastern pipistrelle, the Indiana bat, Keens myotis, the small-footed bat and the Eastern bat. (The animals come in an amazing variety: Some resemble hounds, others badgers and still others have huge ears).
First, the bat conservators attack the myths.
Bats cornered in houses do not attack people, Ms. Hughes explained. Usually, animals that blunder into living areas are panicky juveniles that swoop from corner to corner in an effort to keep airborne in a confined space, find an exit and avoid being swatted.
"If there's a bat in the house, take a deep breath, turn on the lights, open the windows, stand by the wall and watch them fly -- they're wonderful acrobats, and they'll find their way out," Ms. Hughes said.
(The lights help the bats find their way out. Despite the well-worn expression, none of the planet's 1,000 bat species is blind.)
People standing outside are sometimes frightened by dive-bombing bats. But Dr. Valega explained that the heat from people's bodies attracts insects. And bats, using their unique ability to navigate by echolocation, loop, dive and roll overhead to snatch those insects out of the air. No North American bat is interested in biting anyone.
Laura O'Keefe asked Ms. Hughes about reports, now more than two decades old, that bats can survive a rabies infection, carry the disease without showing any symptoms and transmit it to other animals. But bat experts say that study has been discredited.