Take a moment to give thanks for cockroaches and houseflies. They just might save your life someday.

Virginia Commonwealth University entomologist Karen Kester has found the much-maligned insects are good at detecting harmful chemicals, viruses and other potential threats to people.

If, for example, you want to know if a building contains anthrax, or if a room was used as a bioterror lab, you can catch insects in the area and test them for the harmful materials, Kester said.

"I'm not the first to discover that insects pick up stuff," said Kester, 56. "I'm just the first one to exploit it."

Since May 2001, Kester has received about $1.6 million in grants from agencies related to the Department of Defense to study the use of creepy crawlers in finding dangerous materials.

Initially, the idea was to train insects to pursue certain odors, release the bugs, catch them and test them.

That sounded to Kester like a lot of extra effort.

"So I thought, let's just see what's on the insects that are already out there," Kester said.

She spoke in her VCU office filled with books on insects and biology, as well as bug pictures and toy bugs. If you work with insects, she said, it helps to have a sense of humor.

People can collect samples from places suspected of contamination, but that could put lives at risk. Plus, bugs can go places people can't.

Cockroaches, crickets and houseflies are among the best of the diminutive detectives, Kester said, because they are abundant and they get around.

Roaches and crickets are active at night. Flies are active in the day. The roaches crawl. The flies fly. "So you are sampling different parts of the environment."

In tests at the Army's Dugway Proving Ground in Utah, insects including flies, moths and wasps successfully detected harmless bacteria substituting for anthrax, Kester said.

Her research also has shown that insects can pick up human DNA, probably from sloughed skin cells.

"There is no one bug that's the best" at detecting, Kester said. "It depends on what you're looking for and where you're looking for it."

Some insects, for example, inhabit caves -- a helpful trait if you are looking for a certain person who might be hiding in one.

Jokingly, because she doesn't know how her insects ultimately will be used, Kester said, "I use bugs to find stuff -- stuff like anthrax, bombs and Osama bin Laden."

Animals have long been used to detect threats to people, going back to the days when miners carried canaries into coal shafts. Distressed or dead canaries signaled the presence of dangerous gases.

Trained dogs are used to sniff out bombs, cadavers and drugs, said Danyel Olson, a Johnson County, Kan., Health Department epidemiologist who follows the use of animal "sentinels."

And blood tests of so-called sentinel chickens help health officials monitor such mosquito-borne threats as eastern equine encephalitis and West Nile virus.

"Animals are really good indicators of what's in the environment," Olson said.

Kester calls insects "flying or crawling Q-Tips."

Roaches and flies are particularly effective monitors because they will eat almost anything and -- get this -- they are clean freaks.

"They don't like to be dirty on the outside," Kester said, "so they are constantly grooming."

During grooming, the insects ingest materials they have brushed against, and those materials can remain in the bugs for days.

Kester catches the insects in various traps and grinds them up for testing by sophisticated lab instruments.

"That's the sad part of it. You have to kill insects. They are sacrificing themselves for humans."

The bugs' potential usefulness extends far beyond the military and homeland defense, Kester said.

They could help police check a suspect's room for cocaine or assist an environmental agency in finding pollution near a factory, among other uses.

Kester has been assisted in her research by VCU biologist Bonnie Brown and about two dozen students.

After years of study, she is in the report-writing phase. After that, the bugs may get a chance to work in the real world.

Kester hopes her research will help humankind -- and give insects some positive publicity for a change.

So, squash not: The bug you save might get a chance to return the favor.
Contact Rex Springston at (804) 649-6453 or rspringston@timesdispatch.com.