sad thing is someone kept that as a pet and then just let out out in the wild.
they're kind of smart and really just trying to survive. real irresponsible
[h2]Of mice and mines: trained rats search for explosives, tuberculosis[/h2]
By
Thomas Wilburn |
Rat at work
According to the International Campaign to Ban Landmines, an estimated15-20,000 people are killed by landmines each year. Detecting thosemines—without setting them off—is a dilemma that faces many post-conflictregions of the world. But Bart Weetjens may have found a six-pound solutionto the problem: the African giant pouched rat. Working for
APOPO, a Belgian organization founded toexplore the idea, Weetjens has successfully trained rats to locate landmines by smell. The animals have also been trained to identify tuberculosisfrom samples, a development that may prove equally promising.
How did he come up with the idea of using rats for these detection problems?In a Skype interview from his office in Tanzania, Weetjens confessed thathe's always been interested in helping Africa but was initially stalled forsolutions. "I wanted to do something in the real world, somethingappropriate to the environment," he told Ars.
In the early 1990's, when itbecame a
cause célèbre for Princess Diana and others, Weetjens beganlooking into landmines. In travels to Mozambique and Angola, he watched astrained dogs searched for buried explosives. But dogs are expensive (in theneighborhood of $25,000), and many were lost to disease or the mines theywere meant to detect. There had to be a better way.
The breakthrough came when Weetjens saw an article in which gerbils had beentrained as a "black box" vapor detector. He knew that those rodents couldn'tbe his choice: "way too nervous… but rats could do the job." After searchingfor grant money for more than two years, he was able to begin breeding tamepouched rats (a hardy, adaptable African species) for training. Beginningwith a stock of thirty animals, APOPO has now trained more than 120free-running "Hero Rats," twenty-three of which are certified by aninternational agency as equal to dogs in effectiveness.
The similarities don't actually end at the certification. Like dogs, somerats can be easier to train than others. On average, the rats take 10-12months to be fully trained for mine-sniffing, Weetjens said, a processthat's complicated by the distracting stimulus of the outside environment.The rats are trained using a clicker and a banana reward (again, much likedogs, except for the fruit), and they've had a graduation rate of about oneout of every four "students."
Successfully trained rats indicated thelocation of mines by pointing their noses directly at the ground for morethan five seconds. "That's a very long time for a rat," noted Weetjens,although he added that some also develop circling or scratching behavior asan indicator. The rodents wear harnesses and run along strings laid outacross the suspected area, ensuring that they cover the entire grid. And atsix pounds, they're too light to set off the explosives by accident.
A mine-detecting rat working its grid
As exciting as this may be, Weetjens also sees a great deal of promise inthe newer tuberculosis detection research. Tuberculosis-sniffing rats havesubstantial logistical advantages over traditional techniques. In
preliminary tests, a pair of the animals were able to detect 86 percent ofinfected TB samples, with a 10 percent false-positive rate. Clearly, they won'treplace a full lab for accuracy, but the rats are able to check 40 samplesin only seven minutes—a task that would take an entire day for atechnician.
Weetjens hopes that they can be used as a portable screeningtool, one that can be located near slums and other at-risk areas. Thedisease kills about 1.6 million people per year, according to the WorldHealth Organization. And since many tuberculosis cases in Africa accompanyHIV, a fast screening technique is a perfect opportunity to educate patientsabout the disease.
What's the future for these not-so-stupid pet tricks? Weetjens isn't rulingout new directions, including commercial applications—sustainable fundingfor testing with rats (as opposed to testing
on rats) isn't easy tofind. But his ultimate aim remains humanitarian: Recent research intodiagnosing cancer with animals is one possibility, as are "rescue rats"—therodents are small and light enough to slip into collapsed structures insearch of trapped occupants. And for right now, Weetjens seems pretty happywith the progress of his own personal rat race.