Giant Rat Detectives
One of APOPO’s scent detecting HeroRats sniffing for landmines. (Image: apopo.org)
We have all heard of sniffer dogs but what about sniffer rats?
There are many species out there with a powerful sense of smell who can detect odours that we are oblivious to. Dogs’ ability to sniff out drugs, explosives, and even diseases, has been given lots of Press. But why not employ other species who are just as capable of such feats?
Rats and mice are renowned for their intelligence, their problem-solving skills, and for their amazing sense of smell. And yet they are villified and largely seen as pests. So APOPO, a Belgian global non-profit organisation, who are developing scent detection technology, are instead harnessing their rodent powers for good. Quite literally, as they are placing rats in harnesses to sniff out landmines, and even using their noses to detect and help prevent the spread of tuberculosis. Aptly naming these professional sniffers their HeroRats. The perfect sidekicks to HeroDogs, APOPO’s canine scent detection counterparts.
The Gambian pouched rat (Cricetomys gambianus), otherwise known as the African giant pouched rat, grows to around 0.9m long from nose to tail tip. Making them large enough to harness and work with easily. They are highly intelligent, taking only 9 months to train, and can live for 5-7 years. They are native to Africa, so innately resistant to subtropical diseases, as well as readily accessible to some of the countries most at risk from unexploded ordinance (UXO) and tuberculosis. And above all, they have an astonishing sense of smell. Making them the ideal candidates to become HeroRats.
The Landmine Problem
Countries globally have issues with UXO such as landmines, there are thousands of injuries and fatalities caused by them every year. Beneath the ground, invisible to us, they pose a serious threat. Human based detection methods such as metal detectors are inaccurate, inefficient, and high risk. They cannot differentiate between a coin, shrapnel or a mine. All metal is detected, meaning that time is wasted, and the risk of accidental detonation goes up.
A HeroRat receiving a reward from their handler. (Image: nbcnews.com)
The HeroRat Solution
HeroRats are trained to find TNT, so solely detect explosives. Through positive reinforcement with clickers and treats whenever they find TNT during training, they know what they are looking for and what to do when in the field. Rats are attached to harnesses held by human handlers sweeping suspected UXO sites. When they sniff TNT, they scratch the ground where they have found it, so that the spot can then be carefully marked, and the mine removed. HeroRats can pinpoint TNT over large areas in a short period, much as sniffer dogs can. But they are light enough not to set off mines, they do not bond with one handler alone, readily working with anyone, and cost less to train, transport, and care for. In many ways making them the safer, more cost-effective detection option.
Sniffing out disease and saving lives
Disease alters cell behaviour, causing different biomolecules to be produced than when cells are healthy, apart from invading pathogens themselves leaving behind a trail. Sniffer animals smell the difference, allowing them to detect sickness. The faster disease is detected the better. The change in smell is often evident before symptoms begin to show, lab analysis of samples can take too long and may not detect a disease in its earliest stages. So, by also using sniffer animals, diseases can be stopped in their tracks early on. Halting their progression, preventing their spread, and saving lives.
Tuberculosis Prevention
APOPO have trained HeroRats to sniff sputum samples to detect the presence of tuberculosis. Again, through positive reinforcement with clickers and treats whenever they sniff a positive sample, they learn which samples to signal at. If they find a tuberculosis positive sample, they hold their nose over it for several seconds to indicate to the handler that this person is infected. Pinpointing patients in need of further care.
With further research and training, the applications for these HeroRats’ and HeroDogs’ sniffing abilities could be all but endless. And there are so many potential other detection species out there. Through promoting programmes and research such as this we can hopefully find ever more efficient prevention methods and solutions to diseases and disasters.
Read more about APOPO’s work at www.apopo.org.
References
https://www.wayfairertravel.com/inspiration/hero-rats-finding-mines-saving-lives/
Further Reading
https://www.freethink.com/society/landmines
https://www.frontiersin.org/articles/10.3389/fevo.2022.960757
