He bags big clients because he keeps his head in the bug game, studying new techniques with his mentors who include Robert Corrigan, the esteemed New York rat czar.
"Marty is a unique rodent-control expert," Corrigan said, "because he possesses two important characteristics: keen observation skills and an intense interest in the scientific aspects of pest control."
To Overline, the efficient eradication of rats, rodents, cockroaches, flies, ants, spiders, and ticks is a daily virtuosity, achieved by wriggling through tunnels and slipping into passageways where few people venture.
More than three decades in the business have made him philosophical. About man's stance atop the food chain. About planetary ecology. About how couch cushions seem to hide whole pantries of old food.
"Number one species on the planet? We are," he said. "Number two? Mice."
And the solution to staying on top?
"Keep it clean. Sanitize."
Because, in all seriousness, he says, controlling bugs is more than a punch line - it's a matter of public health.
"He's a wealth of knowledge," said MeeCee Baker, executive director of the Pennsylvania Pest Management Association, where Overline heads the Bedbug Committee. "The industry is very proud of Marty."
Overline doesn't advertise his firm, Aardvark Pest Management. He doesn't put the company logo on his trucks. He didn't choose the name because the double-A beginning would put it first in the phone book - it was picked at random by a friend.
He depends on word of mouth. And that's been enough.
In 1999, the Penn Current recorded his campus take: Rats. Squirrels. A snake in the Sansom West residence hall - actually a 12-foot Burmese python, left behind by two students. (Overline wrangled the serpent into a laundry bag.) A possum in the School of Dental Medicine. (He picked it up and carried it off, the animal so paralyzed with fear that it, well, played possum.) A hawk that stalked the quad, feasting on pigeons. (He left it alone. Any bird that eats rodents is his friend.)
The fact is, almost every big commercial enterprise will have bugs and mice. Overline annihilates the pests only as a last resort.
He practices what's called "integrated pest management," or IPM, which involves a series of evaluations and calculations - a sort of Bug CSI. Instead of immediately bombing a space with pesticide, he asks: Why are the creatures gathering here? How are they getting in? What helps them stay?
Basically, Overline tries to persuade pests to leave before he breaks out the poison. That can mean blocking their access to an area, perhaps by filling cracks in a wall. It may mean removing nests, eliminating food sources, or cutting off water supplies.
"Smart guy," said Lyn Garling, manager of the IPM program at Pennsylvania State University. "You really need to be almost a sociologist to work in the field, because people freak out about bugs."
Overline, who turns 52 on St. Patrick's Day, is a divorced father of three and a city boy to the core. He was raised in Mayfair, keeps his office in Frankford, and lives in Holmesburg.
Two weeks after graduating from Father Judge High School in 1978, he enlisted in the Air Force. His grandfather had fought in World War I, and his father landed in Normandy days after D-Day, so it made sense he would enter the military.
The Air Force offered a job that to his teenage ears sounded pretty darned glamorous: engineering entomology specialist. It turned out entomology is a fancy word that means "the study of insects."
Overline was assigned to Rhein-Main Air Base in Frankfurt, West Germany, for decades the hub for U.S. military forces in Europe. In the 1980s, the sprawling base hosted thousands of arriving and departing soldiers, a churn that helped spread pests and generated tons of food waste.
It was a great education.
Overline carried it into civilian life, working as a subcontractor and then starting Aardvark in 1994. Today, he figures his business is worth a million bucks. He has 10 employees, including his son. And everyone is busy.
The reason? People. In modern society, people don't just work in their work spaces - they eat in them, sometimes breakfast, lunch, and dinner, dropping crumbs and bits of food onto carpets and computer keyboards. People keep food in their desks - a beacon for bugs.
"Then I get a call," Overline said.
Some companies set up Dumpsters, then decide not to empty them until they're full. That can take weeks - "a lifetime in the insect world." What do the bugs do? They breed. As have they always. Overline is undertaking an informal study of colonial American hygiene (not good) and its impact on public health (also not good). Part of the difficulty came from people sleeping on beds of hay that were invariably infested.
Today, bedbugs are making a comeback. And Overline is helping the industry deploy a new weapon: Dogs.
Their sophisticated sense of smell has sniffed out everything from people to explosives to drugs. Now, dogs are being trained to find bedbugs. University of Florida researchers found that dogs were 98 percent accurate in quickly locating vials of bugs hidden in a hotel room.
Overline's dogs - Heidi and Chase Mutley - can do an inspection in minutes.
"Some days, they don't want to work," he said. "They take days off. There's no dog union. And they just stop working."
Overline serves on the Canine Insect Detection Division of the National Pest Management Association, where he helps colleagues learn about bug-sniffing dogs.
Bedbugs have not been found to transmit illnesses, but they inflict awful bites. Ticks can transmit 10 diseases. The plague that wiped out a third of Europe in the 1300s was spread by fleas.
"My real job," Overline said, "is, I protect people's health."
Contact Jeff Gammage at 215-854-2415 or email@example.com, or follow on Twitter @JeffGammage.