Giant African rats may soon be the key to fighting illegal wildlife trafficking.

New research from nonprofit APOPO, published Oct. 29, shows that African giant pouched rats can be trained to identify illegally trafficked wildlife through scent detection. APOPO specializes in training giant pouched rats and technical survey dogs.

Illegal wildlife trafficking is the fourth largest global illegal trade after narcotics, human trafficking and counterfeit products, according to U.S. Immigration and Customs Enforcement.

"Current methods to combat illegal wildlife trade and screen these shipping containers, such as X-ray scans, are expensive and time-consuming," the study says. "Scent-detection animals present an innovative approach to combatting illegal wildlife trade, as animals may be better suited to distinguish between organic materials and less susceptible to visual concealment methods."

Here's how the rats were trained, tested

APOPO conducted its research at its research headquarters in Morogoro, Tanzania in eastern Africa between December 2017 and December 2021. Eight rats, all previously socialized to humans and habituated to various environments, were used throughout the entire study.

In the first stage of training, the eight rats became acquainted by smell with four wildlife samples: pangolin scales, African blackwood, rhino horn and elephant ivory. Then, the rats were provided several "non-target items," such as electrical cables, plastic hair wigs, new cotton socks, coffee beans, cardboard, washing powder and unshelled raw peanuts, according to the study report.

To become acquainted, rats learned how to hold their noses to holes in their cages where items were placed. Favorable actions were reinforced with flavored pellets.

The next step tested what the rats learned, mixing wildlife samples and non-target items to see if the rats could select the former.

What were the results?

By the end of the study, all eight rats were able to differentiate the four wildlife samples from 146 non-target items, according to the study report.

Additionally, the rats proved to have quite incredible memory. In one test, all of the rats displayed prefect retention of pangolin scales, African blackwood or rhino horns after not encountering the samples for eight months.

"Although we did not test retention after a 12-month period, these findings suggest that rats’ cognitive performance in retention of targets is on par with that of dogs," the study report states.

The importance of breaking out of the lab

Perhaps the key limitation from the study is that all training and testing took place in a controlled laboratory environment, which does not reflect situations in which rats would be tasked with sniffing out trafficked wildlife. Further research is necessary to determine is giant pouched rats can still have a successful detection rate in the real world, the study report states.

Next steps

Testing and training rats in real-world environments is the clear next step for this ongoing study.

For these excursions, the rats will wear custom-made vests that feature a small ball on the front that emits a beeping sound, according to an interview with the scientists published by Frontiers Media. When a rat wishes to alert a handler of a detected target, it will use its front paws to pull and sound the ball.

Greta Cross is a national trending reporter at USA TODAY. Follow her on X and Instagram @gretalcross. Story idea? Email her at [email protected].