Research assistant Victoria Flores captures bats near their roosting site at a 1735 Colonial house in Warren. Flores says she is not afraid of the creatures, despite their scary reputation. “They’re so adorable,” she says.

The Providence Journal / Bob Thayer

Steven Butterworth stands in the twilight shadows of the tall trees surrounding his yard and looks on in quiet desperation as the sky darkens above his old, rickety house. His family has owned the 275-year-old Colonial in Warren since it was built, yet he is powerless to evict a gang of nearly 100 squatters.

“That’s where the biggest one comes out, out of that corner,” he says, pointing to the roof line

Soon, the large trespasser drops down from its hiding spot and circles overhead like a winged ink spot against the gray-blue sky.

“Hey there! That is a fat bat!” says Victoria Flores, watching it escape the nets she and her crew put up.

All the while, Brown University Prof. James Simmons, in his khaki shirt and khaki trousers, directs the operation. Without live bats to bring back to his laboratory, the veteran researcher and his team of young scientists would be left in the dark when it comes to understanding how the nocturnal creatures take to the nighttime sky and, like blindfolded stunt pilots, manage to dodge trees and buildings while plucking itsy-bitsy bugs out of the air.

Nor would the Navy and other undersea operators be able to benefit from the scientists’ continuing sonar discoveries.

Toy bats of all sizes hang from the ceiling of Simmons’ office in the basement of Brown University’s Hunter Laboratory of Psychology. A comic book illustration of Batman is stuck to the wall. Bat puns, caped-crusader references — Simmons embraces all of the humor inherent in his work.

He also understands how freaked out some people are by his fanged Halloween icons. While they are legitimately feared as rabies carriers, bats play a vital role in nature by preying on mosquitoes and other insects. They also make fascinating research subjects.

In his youth in Quincy, Mass., Simmons, who liked catching turtles and snakes, had no such luck when he tried netting bats.

“My dad said they used radar,” a 1940s discovery, Simmons said. “I forgot about it for about 20 years.”

Not until he went to Princeton University for graduate studies in psychology did Simmons revisit bats and sonar, completing a doctoral dissertation titled “Perception of target distance by echo-locating bats.”

Ever since, Simmons, 67, has devoted himself to studying bats — a career that has spanned four decades, multiple universities, dozens of research papers and travel to bat dwellings around the world. But it’s here, at Brown, where he has remained since 1984.

In a room next to his office — like a parent close to a child’s bedroom — are the cages that are home to Simmons’ band of big brown bats. Only lab personnel, who are inoculated against rabies, are permitted inside.

Down the hall is a door with a sign that says “Batlab.”

“Come on in,” says Simmons. “This is sort of like working in a submarine.”

The small, dark room feels even more closed in because layers of material cover the walls and ceiling — copper fabric underneath to block radio waves and thick black soundproofing on top to absorb unwanted echoes.

During sonar experiments, a bat is let loose into the nearly pitch-black space and must navigate around an array of hanging metal chains. Thermal imaging cameras capture the bat’s movements. Microphones on the walls record its high-frequency sounds, which can’t be heard by humans. A tiny helmet placed atop the bat’s head carries a miniature microphone to record the echoes of these sounds, as they bounce off the chains back to the bat’s large, pointy ears.

What the researchers learn about how the bats almost instantly “see” the chains can have valuable applications underwater, where acoustics are the only reliable way to create images, Simmons says. The problem with sonar, however, is that it takes computers time to interpret such data. The development of “real time” sonar, he says, could lead to dramatic improvements in torpedo technology, guidance systems for autonomous submersibles, intruder detection in bays and harbors, and scanning ship bottoms for terror devices. The research is partly financed by the Office of Naval Research and the National Science Foundation.

But the work couldn’t continue without replenishing his bevy of bats. That’s why Simmons is asking homeowners for their unwanted bats. (Reach him at: james_simmons@brown.edu)

For Steven Butterworth, Simmons can have all he desires.

“There’s always been bats,” he says outside of his 1735-plaque house on Child Street. But, he says, “It’s progressively gotten worse.”

Bats have gotten into the house three or four times, sometimes flapping around upstairs bedrooms.

When Simmons first checked out the house, he was as thrilled as the Butterworths were aghast.

“There’s a lot of bats,” he says. “There’s guano half a foot deep in the attic.”

On three previous nights, Simmons’ team collected nearly 40 bats. Now, on a fourth evening they are back for more.

“We’re the bat busters,” quips Simmons, who is joined by research assistant Flores, 24, graduate student Alyssa Wheeler, 22, and graduate student Jason Gaudette, a sonar engineer for the Naval Undersea Warfare Center.

The team hoists enclosed nets fastened to extension poles to cover sections of the roof line where the bats get into the attic, between walls or into nooks and crannies between clapboards and trim. The only bit of gadgetry — what you might expect to find on Batman’s utility belt — is a “bat detector” in Simmons’ hand. Tuned to the frequencies of bat sonar, its speaker comes alive with their high-pitched chirps when darkness falls and they leave their roosts. At least 20, however, escape capture.

“Catching bats is an inexact science,” says Wheeler.

Neither she nor Flores is afraid of bats. Nor do they have a problem handling them.

“They’re so adorable,” says Flores.

She climbs a short ladder next to a gutter pipe. Then she holds a pole with a net on the end of it over a spot where the Butterworths saw several bats exit.

“They’re right there, I can hear them,” Flores says.

After several minutes, one lands in the net. “Yes! Stay! Stay!”

She quickly chokes off the net with her gloved hand to prevent the squeaking bat from escaping.

“He just peed all over me!” she says. After a closer look, she gushes and says, “Oh, he’s a baby!” By the end of the evening, five more are caught.

“That was one of the more successful nights,” Simmons says.

FAQsBIG BROWN BATS

What are they like?

The members of the species Eptesicus fuscus are furry and warm-blooded.

Just how big are big brown bats?

They are about 4 to 5 inches long, have a wing span of 11 to 13 inches and weigh just a half to five-eighths of an ounce.

What do they eat?

Insects, including beetles, katydids, wasps and mosquitoes. They capture their prey in flight, which causes their signature flying style of sudden changes in direction.

What do they do in winter?

When it’s cold, they hibernate. It’s thought that some spend the winter in caves, while many seek warmth inside buildings.

How long do they live?

Female bats have just one or two “pups” per year, but they live for four to six years.

Are they dangerous?

Bats are helpful because of the large numbers of flying insects they consume, but they do have the potential to spread rabies. They rank behind skunks and raccoons for rabies cases, and it’s estimated that less than 1 percent are infected with the disease. Still, state officials advise avoiding all contact with bats.

rsalit@projo.com