“Backpacker rats” can help rescue earthquake survivors

Buildings don’t collapse very often, but when they do, it’s catastrophic for those trapped inside. Natural disasters like earthquakes and hurricanes can destroy entire cities, and for search and rescue teams trying to find survivors, it’s an arduous task.

But an unlikely savior is being trained to help in these missions: rats.

The project, conceived by Apopo, a Belgian non-profit organization, is outfitting rodents with small, high-tech backpacks to help rescuers search for survivors among the rubble in disaster zones.

“Rats are generally quite curious and like to explore – and that’s key to search and rescue,” says Donna Kean, behavioral research scientist and project leader.

In addition to their adventurous spirit, their small size and excellent sense of smell make mice perfect for locating things in tight spaces, says Kean.

Currently, rats are being trained to find survivors in a simulated disaster zone. They must first locate the target person in an empty room, pull a switch on their vest that triggers a beep, and then return to base, where they are rewarded with a treat.

While the rodents are still in the early stages of training, the NGO is collaborating with the Eindhoven University of Technology to develop a backpack equipped with a video camera, two-way microphone and location transmitter to help rescuers communicate with survivors.

“Along with backpacking and training, mice are incredibly useful for search and rescue,” says Kean.

backpack mice

The organization has been training dogs and rats at its base in Tanzania to detect the smell of landmines and tuberculosis for more than a decade. Their programs use African giant rats, which have a longer lifespan in captivity of about eight years compared to the average brown rat’s four years.

While the search and rescue project only officially launched in April 2021, when Kean joined the team, Apopo had been trying to get the idea off the ground for years, but lacked funding and a search and rescue partner to back it up. it.

But when the voluntary search and rescue organization GEA approached the NGO in 2017 about the possibility of using rats in its missions, the team began exploring the idea.

A key component to the search and rescue mission was the technology to allow rescuers to communicate with victims through the rats. The association didn’t have that – until electrical engineer Sander Verdiesen got involved.

Looking to “apply technology to improve lives” during his Masters studies at Eindhoven University of Technology, Verdiesen interned at Apopo in 2019 and was tasked with creating the first prototype of the mouse backpack, to help first responders get a better idea of ​​what was happening inside disaster zones.

The prototype consisted of a 3D-printed plastic container with a video camera that sent live images to a receiver module on a laptop, as well as saving a high-quality version to an SD card. He was attached to the mice with a neoprene vest, the same material used for wetsuits.

Verdiesen flew to Tanzania to test the equipment and says that initially the mice “didn’t really know how to handle it” but quickly adapted. “In the end, they were just running around with the backpack, no problem at all,” he adds.

Big challenges for small technologies

With the backpacks working “better than expected”, Verdiesen continued to refine the design even after his internship ended, now as a volunteer. But downsizing the technology and adapting it for disaster zones was not easy.

GPS cannot penetrate the dense rubble and debris of collapsed buildings, says Verdeisen. An alternative is the Inertial Measurement Unit, a location tracker worn on the soles of firefighters’ boots.

“If you’re walking, your foot will be stationary with every step – that’s where you can recalibrate. With mice, we are yet to discover that,” he says. Other engineers are working on similar projects, so he hopes they can find a solution.

Verdeisen is also looking to include more technology in the next version, such as a two-way microphone, while reducing the size. Weighing around 140 grams, the prototype was twice as heavy as originally intended – although Verdeisen says volume was a bigger issue, at 10 centimeters long and 4 centimeters deep.

“The mice were walking against something they would normally be able to pass and then suddenly they can’t,” he explains.

To make it “as small as possible” without losing any functionality, Verdeisen plans to integrate everything on a single printed circuit board, which will free up more space. This updated version of the backpack should be ready later this year, and he hopes it can one day help rescuers “locate someone who would otherwise not be rescued.”

rodents to the rescue

Meanwhile, in Tanzania, Kean is increasing the complexity of the rats’ training environment, “to make it more like what they might encounter in real life.” This includes adding industrial sounds like drilling to mimic real emergencies.

So far, the results are promising: from his observations, Kean says the mice are responding well to the increasingly difficult simulations: “They have to be super confident in any environment, under any conditions, and this is something these mice are naturally good.”

Handled from birth, rats are exposed to a variety of environments, sights, sounds and people as part of a “habituation process,” which makes their gradual exposure to more extreme situations less stressful, according to Kean.

As animals are at the heart of Apopo’s projects and missions, their welfare is a priority. The animals are trained in 15-minute sessions, five days a week, and live alone or with siblings of the same sex in domestic cages, which is also where they spend their days when they retire from working life.

With a diet of fresh fruits and vegetables, they also have daily playtime in a personalized playroom — although for the search and rescue rats, training is very similar, “just with a little direction,” says Kean.

The program is still under development, but Kean estimates it will take at least nine to 12 months to train each mouse.

For the next stage of training, Kean says the team will create “levels to mimic several floors of a collapsed building” and will approach “real-world scenarios”.

Once the mice are confident in more complex environments, the project will move to Turkey, where GEA is based, for further preparation in more realistic environments. If all goes well, the mice would potentially get into real-life situations.

For now, though, Kean and the team in Tanzania are focused on getting the mice through their first phase of training — and hoping that one day, in the field.

“Even if our mice find only one survivor in a wreckage site, I think we’d be happy to know that it made a difference somewhere,” says Kean.