Rats are not animals that humans generally feel a lot of affection for, but now they may demand at least some respect. In Tanzania, the giant African pouched rat is being trained to detect deadly landmines. The researchers behind the project hope to get the rats certified as internationally valid demining tools and deploy them across the world, starting in Mozambique. They believe the rodents can speed up efforts to rid the world of an estimated 50 million landmines, in about 60 countries.
At the training center, Abdullah Mechouv opens a cage containing a huge rat.
"Her name is Lisa. For me, it is easy to identify her because [I've been] working with her for a long time. She's licking my arms so I know it's Lisa. Lisa is licking frequently," she says.
Lisa, as you might guess, is Mr. Mechouv's favorite rat, but she's not exactly a stunner. This giant African pouched rat is more than 30 centimeters long, not including her enormous dark brown tail.
Mr. Mechouv is a trainer for the first-ever rat demining team.
Early each morning in a dusty training field surrounded by the beautiful Tanzanian Uluguru Mountains the rats are put into harnesses, attached to 10 meters of rope, and sent to work. With their noses to the ground, over 60 rats get to work scanning the training field.
At this session, trainer Mussa Omary, is working with the advanced class, including a rat named Saskia.
"She can sniff and scratch, sometimes bite," he explains. "That's the indication where the mine is. One click and I give her a reward. Now there is a mine. There, where she is searching, she's sniffing."
Mr. Omary carries a small toy that makes a clicking noise, telling the rat she has done well and will get a treat.
"This is a real mine. You see the indication by scratching. Click means rewards ... peanuts, the other guy has bananas," he explains.
Weighing less than 1.5 kilos, Saskia is far too light to trigger a landmine.
But the rats have some disadvantages. It takes each one an average of 30 minutes to check a small area just of just 100 square meters, and only if they are hungry. And the rats are only about 70 percent accurate, so each field must be checked by three rats. After that they are tired, and to check a larger area would require more rats, or waiting until the next day.
But the trainers, who call their organization APOPO, say these specially trained giant African rats also have many advantages for de-mining. They are found locally, which means they are immune to local tropical diseases. They breed prolifically and learn quickly, without relying on an individual relationship with a trainer, as dogs do.
Landmine specialist Graeme Abernathy is an advisor to the Mozambique government. He is the man who will decide if the rats meet international de-mining standards, before they can be deployed. If they pass the test, their first real de-mining job would be in Mozambique.
"We visited the APOPO team. We used a similar system to dogs. Of the 17 rats, eight passed," he says. "Every dog has to indicate every mine and every rat had to [do the same]. Eight rats did. They have been licensed now. Dogs are expensive. It will be interesting to see the productivity versus the cost, how worthwhile they are. It's all down to dollars."
The team is already looking into another way to use the rats - as what they call 'remote sensory devices' - a system they call REST. Christophe Cox is the group's product developer.
"REST is a system whereby very quickly you want to scan a certain area on the presence of explosive vapors or mines," he says. "So what we do, we have people walking with a vacuum pump taking air samples over track or safe walking ground. They take a sample every 100 meters of road, bring into a laboratory set up where the rats are sniffing one sample after another. They will indicate if the sample contains explosive traces."
And Mr. Cox says the rats and the REST air sample system may prove useful in sniffing out another deadly threat - tuberculosis. If the rats can detect tuberculosis in its early stages, people can be saved, and the credit for that will go to the perhaps not loved but maybe increasingly respected giant African rats.