The idea of having trained animals help with difficult tasks isn’t new. Dogs are the most popular working animals because of their innate loyalty and heightened sense of smell. In other parts of the world, more exotic creatures work for humans. Elephants, with their intelligence and muscle, speed up rural construction projects, and certain species of monkeys have been trained to accomplish the dangerous task of harvesting coconuts from tall, unsteady trees.

In the past decade, a new and unexpected animal has joined the workforce: the rat.

In Africa, rats have been trained to do several types of jobs, and some of the tasks that they perform save human lives.

One of the most notable examples of this unusual phenomenon: using rats to help clear land mines. A Belgian NGO called Apopo came up with the idea of training Gambian pouched rats (also called giant African pouched rats) to sniff out land mines in Mozambique. The country continues to have problems with land mines years after the end of a bloody civil war. The program was so successful that it has expanded to Angola and Southeast Asia.

Once you understand the advantages of rats, the idea of using them for this kind of work doesn’t seem strange at all. Like dogs, rats have a keen sense of smell, and they can be trained to seek out certain odors. They are able to work more independently than dogs, which require more direct supervision, an important practicality when it comes to minefields. Also, rats — even the large Gambian pouched rats — are too light to set off most mines, meaning they face little danger in the field.

Rat-based mine detection isn't a complicated process. A rat is harnessed to a line held by two handlers. The animal moves up and down the line, methodically searching the field. The handlers mark the spots where mines have been detected, and the explosives are later removed by a bomb disposal team.

The rats’ small size makes them easy to transport. Overall, a sweeping operation using rodents is quicker and much cheaper than if the same task with high-tech equipment.

This video gives a look at a day in the life of rats in the training program:

Rats' sense of smell makes them perfect for other types of detection jobs, too. The same species that sniffs out mines has been trained by Apopo to detect one of Africa's most lethal diseases: tuberculosis. Rodents trained to recognize TB in saliva samples are able to give a quick, accurate diagnosis. The rats can work much faster than a lab technician, vetting a day's worth of samples in a few minutes.

The Gambian pouched rat isn't the only rat species that works with humans. In the Netherlands, police forensics teams use common brown rats to find gunpowder residue. There are even animal therapy programs for autistic kids in the United States who have traded in their companion dogs for domesticated rats. The rats are less expensive and require less space yet evoke the same positive response from patients.

They might not win the title of man's best friend anytime soon, but rats are proving that they are one of the world's most useful working animals.

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