Will Every Rat Have Its Day?
CANINES HAVE been the beast of choice for explosives detection because of their tremendous olfactory senses and their compatibility with humans. But promising research into the sniffing potential of other life forms suggests that the field should not be allowed to go to the dogs.
Giant African rats, parasitic wasps, moths, pigs, and other creatures have been harnessed by researchers for their ability to smell volatile compounds, and many have shown high rates of detection, though perhaps not a readiness to work with humans.
One Belgian company has reported success using rats to scour the fields of Mozambique and other countries for landmines. Company officials say the versatile vermin can be trained in six months. They also cost much less than explosives-sniffing canines.
At the University of Georgia's College of Agricultural and Environmental Sciences, biological engineer Glen Rains has jerry-rigged a tool called the Wasp Hound to harness the keen sense of smell of parasitic wasps to detect aflatoxin, a poison that attacks crops. Rains claims that the insects can be trained in a remarkably quick five to ten minutes, which is critical since their life span is an evanescent two weeks.
Bees have been the subject of similar research for years, particularly at the University of Montana and Montana State University. Montana State's Joseph Shaw says that bees can be trained to detect landmines with a 97.5 percent accuracy.
Honeybees can be trained to seek out a given chemical by adding it to their syrup feed, encouraging them to associate the scent of a chemical with a source of food, which in turn causes them to fly towards and around any source of that chemical they find during their natural foraging.
Bees can be trained to detect a wide range of compounds concurrently, and in low concentrations, says Jerry Bromenshenk, a research professor at the University of Montana. Researchers track bees via LIDAR, a technology similar to radar except that it uses laser pulses rather than radio waves to determine the distance from an object. Bromenshen says that more advanced tracking methods are currently being tested. "We're hoping to go to testing in the minefields this summer," he says.
The use of bees and other nontraditional detectors is receiving serious attention. Last year, the Committee on the Review of Existing and Potential Standoff Explosives Detection Techniques of the National Academies acknowledged the promise of bees, rats, moths, and butterflies for explosives detection. In a paper, the committee recommended feasibility studies to "assess their potential in sensors suitable for standoff detection."
Whether such explosives-detecting insects and animals are the bee's knees or just a lot of empty buzz, the K-9 industry is unlikely to be affected. Bromenshen says that bees are best used as adjuncts to canines. And nobody will dispute that wasps and rats aren't yet quite as endearing as dogs.