Giant Rats on Patrol: Study Suggests Rodents May Help Fight Illegal Wildlife Trade

APOPO’s HeroRATs can detect illegal wildlife products, as shown in a new study. | Image Credits: X/@herorats

A recent study suggests that giant African rats, weighing between 1.5 and 2 kilograms and known for their sharp sense of smell, may soon play a role in combating the illegal wildlife trade. The study was conducted by the nonprofit APOPO in Morogoro, Tanzania, from December 2017 to December 2021, the study demonstrated that these large rodents, also called "hero rats" by their trainers, can detect illegally trafficked wildlife products.

These giant rats, native to the savannahs of southern Africa, have already proven effective in detecting land mines and diagnosing tuberculosis by sniffing out pathogens in samples. Scientists now believe they could be trained to identify illegally trafficked wildlife, such as ivory, rhino horns, pangolin scales, and African hardwood, even when mixed with other substances.

According to the study, the rats’ scent detection capabilities offer a unique solution to a growing challenge. "Scent-detection animals present an innovative approach to combatting illegal wildlife trade," the study explained, noting that these animals can more easily distinguish organic materials and may be less affected by concealment methods.

Currently, wildlife trafficking detection relies on methods like X-ray scans, which can be both costly and time-consuming. Training a detection dog costs about $30,000, and airport scanners can cost anywhere from $30,000 to over $1 million. By contrast, training one of these giant rats costs around $8,000, making it a far more affordable option.

Unlike dogs, which are often paired with the same handler, these rats are adaptable and can work with different handlers. This flexibility makes them especially useful for environments like airports and border checkpoints, where they could be stationed and managed by various officials. Senior research scientist Isabelle Szott, a co-author of the study, highlighted that the rats’ lightweight build allows handlers to lift them to higher locations, such as ventilation systems in shipping containers, where dogs cannot reach.

Though the results are promising, scientists acknowledge that further research is needed to assess the feasibility of deploying the rats in practical scenarios. For field use, the rats would wear custom vests equipped with a small ball that emits a beeping sound. When a rat identifies a suspected item, it will pull the ball with its front paws, signalling to its handler.

By offering a cost-effective, adaptable solution, the APOPO study suggests that giant African rats could play a role in addressing illegal wildlife trafficking, although more testing is needed before they can be deployed in real-world settings.