Buildings don’t collapse very often – but when they do collapse, it’s disastrous for those trapped inside. Natural disasters such as earthquakes and hurricanes can reach the level of entire towns, and for search and rescue teams trying to find survivors, this is a daunting task.
But an unexpected savior is being trained to help: mice.
The project, designed by the Belgian non-profit APOPO, is equipping rodents with small, high-tech backpacks to help first responders search for survivors among the rubble in disaster areas.
“Rats are usually very curious and like to explore — which is key to search and rescue,” says Donna Keane, behavioral research scientist and project leader.
In addition to an adventurous spirit, their small size and excellent sense of smell make mice ideal for locating objects in tight spaces, says Kane.
Rats are currently being trained to find survivors in a simulated disaster zone. They must first locate the target in an empty room, pull the switch on the jacket that whistles, and then return to the base, where they are rewarded with a reward.
While the rodents are still in the early stages of training, APOPO is collaborating with the Eindhoven University of Technology to develop a backpack with a video camera, two-way microphone and a location transmitter to help first responders communicate with survivors.
“Along with a backpack and training, mice are incredibly useful for search and rescue,” says Kane.
APOPO 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 the African giant bag rat, which has a longer lifespan in captivity of about eight years compared to the four years of the common brown rat.
While the search and rescue project was only officially launched in April 2021, when Ken joined the team, APOPO has been trying to launch the idea for years but lacks the funding and a search and rescue partner to back it up. But when the volunteer search and rescue organization GEA reached out to APOPO in 2017 about the possibility of using mice in its missions, the team began exploring the idea.
A key component of the search and rescue mission was technology that allows first responders to communicate with victims via mice. APOPO did not have this – until electrical engineer Sander Verdiesen stepped in.
Researching “Applying technology to improve lives” during his masters studies at Eindhoven University of Technology, Verdesen trained with APOPO in 2019 and was tasked with creating the first prototype of a rat backpack, to help rescuers get a better idea of what was going on inside disaster areas.
The prototype consists of a 3D-printed plastic enclosure with a video camera that sends live footage to a receiver unit on a laptop, with a high-quality copy saved on an SD card. It was fitted to mice with a neoprene jacket, the same material used for diving suits.
Verdesen flew to Tanzania to test the equipment and said the mice initially “didn’t really know how to handle it” but adapted quickly. “Eventually they were running around with their backpack on, no problem at all,” he adds.
With the backpacks doing “better than expected,” Verdiesen continued to improve on the design even after his volunteer tenure ended.
But scaling back technology and adapting it to disaster areas has not been easy.
GPS cannot penetrate the dense rubble and debris of collapsed buildings, Verdesen says. An alternative is the inertial measurement unit, which is the position tracker used in the heels of firefighters’ boots.
“If you walk, your foot will stick out every step or so – you can reset it. With mice, we haven’t found that yet. Other engineers are working on similar projects, so hopefully they can find a solution.”
Verdeisen is also trying to bring more technologies into the next version, such as a two-way microphone, while reducing its size. Weighing around 140 grams (4.9 ounces), the prototype was twice as heavy as originally intended — although Verdesen says bulkiness was a bigger problem, at 10 centimeters (3.9 in) long and 4 centimeters (1.6 in) deep.
“The rats were bumping into something that they could normally get under, and suddenly they couldn’t anymore,” he explains.
To make it “as small as possible” without losing any functionality, Verdeisen plans to combine everything into one printed circuit board, which will save even more space. This upgraded version of the backpack should be ready later this year, and he hopes one day it will help first responders “locate someone who could not have been saved.”
Meanwhile, in Tanzania, Ken is increasing the complexity of the rat’s training environment, “to make it more like what they might encounter in real life.” This includes adding artificial sounds like digging to mimic real emergencies.
So far, the results are promising: From her observations, Kane says mice respond well to increasingly challenging simulations: “They have to be very confident in any environment, under what conditions, and that’s something these mice are naturally good at.”
Mice are handled from birth, and exposed to a variety of environments, sights, sounds and people as part of the “habituation process,” which makes their gradual exposure to more dangerous situations less stressful, according to Kane.
With animals at the center of APOPO’s projects and missions, well-being is a priority. The animals are trained in 15-minute sessions five days a week, and live alone or with same-sex siblings in home cages, which is also where they spend their days once they retire from working life.
By following a diet of fresh fruits and vegetables, they also get daily playtime in a dedicated playroom—although the training is very similar for search-and-rescue rats, “only with a little guidance,” Kane says.
The program is still in development, but Ken estimates that training each mouse will take at least nine to 12 months.
For the next phase of training, Kane says the team will create “levels to mimic multiple floors of a collapsed building” and approach “real-world scenarios.” Once the mice are confident in the 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 rats are likely to enter realistic situations.
For now, though, Kane and the team in Tanzania are focused on getting the rats into their first phase of training — and hopefully, one day they’ll hit the field.
“Even if our rats find only one survivor at the wreck site, I think we’d be pleased to know it’s making a difference somewhere,” says Kane.