Rats can save lives by finding earthquake victims among the rubble

Rats can save lives by finding earthquake victims among the rubble

Rats can save lives by finding earthquake victims among the rubble

Researchers have successfully trained rats to spot landmines, detect tuberculosis and even drive cars, but their next challenge – finding survivors in a collapsed building – may be their bravest. We spoke to Dr. Donna Kean, behavioral researcher at APOPO, an organization at the forefront of training rats to save lives.

Why rats?

They can contribute something that the other technologies can’t, at least for the areas in which we train them. Their sense of smell and trainability are comparable to those of dogs.’ But it’s the small size of the rats that really makes a difference.

At APOPO we work with the African giant opossum [Cricetomys ansorgei]† We taught the rats to detect land mines, because they are too small and light to detonate a land mine. We teach them to detect the smell of illegally smuggled animals in seaports, because they can reach the containers stacked high on top of each other.

For my research on training rats for search and rescue, the main reason is that they can get into the small, tight areas of a rubble site. Search and rescue dogs usually just go around in rubble, hoping that the rats can actually get in, because of all the rubble, because they are so small.

Each request must be a response to a humanitarian challenge and must have our rats’ unique abilities to help. If it’s already there [other] technology is available, and it’s affordable, we’re not going to train our rats just for fun.

How do you train a rat to do these things?

We use positive reinforcement to train them in a basic set of behaviors. So here it is to look for a human, signal to us that they found them and then return to where they were released.

[Training] starts in a very simple environment: a small, empty room. Then we gradually expand and increase the complexity so that it looks more like real life. We can start adding rubble and make the training area look more like a real collapsed construction site.

A person with long brown hair and wearing a blue jumpsuit, looking at a rat on their shoulder

dr. Donna Kean with Jo, one of the rats being trained for search and rescue © APOPO

What happens if they find someone?

They have to activate a switch, which makes a sound. At the moment we put them in a vest with a ball on the collar, with a micro switch in it. The rats are trained to pull the ball when they find someone, which activates the microswitch and emits a beep.

Pulling the ball is not a natural behavior for them, but they can be trained in a process we call ‘shaping’. We start by putting on the vest with the ball on it. The rats are naturally very curious, so when they have the ball hanging there, you can see they’re like, ‘What’s this?’

Read more rodent research:

In the beginning, we amplify them just to touch the ball at all. Then, as is standard with molding, you’d stop amplifying for just touching, so they realize, ‘Oh, I’m not amplifying anymore’. Then they will try harder [to get the reward]† That usually leads to them pulling the ball, and we have to reward them very quickly so they know this is the target behavior. Then we can shape in a similar way until they pull on it for two to three seconds, so it’s a really strong signal for us.

In the field, of course, we will not be able to see or hear the rats. So we’re working with a group of engineers to develop a multifunctional backpack that connects to our computer so we can get a notification when the rats pull the ball. We will know exactly where they are, because the backpacks must also have a location transmitter.

How can they tell the difference between those who are still alive and those who are not?

We’ve talked a lot about this because we’ll only be doing the training with living people and not knowing how they’ll react to dead bodies until they’re in a real-life scenario. However, dog trainers have told us that the scent profile of a person who is alive is very different compared to a person who is dead. Dogs can tell the difference between a living and a deceased person about three to four hours after death.

We thought maybe we should train the rats on some sort of smell that we might be able to get our hands on – it’s hard to know what to call it, but whether we would actually need the smell of death.

But the dog trainers told us that we don’t have to do that, because the smell change between living and dead people is so different, that’s not a problem.

A rat wearing a cream-colored vest navigates a terrain of tires, pipes and other debris

During their training, the rats wear a vest with a microswitch inside a ball that they have learned to pull when they find a victim © APOPO

When will these rats be in the field?

We just started training in August 2021 and we still need to run training trials outside the research environment. We are working with a search and rescue group called GEA, which is based in Turkey, an earthquake-prone country. We hope that next year we can bring the rats to Turkey for trials there, but in terms of going to real disaster areas, real collapsed buildings… it’s very, very hard to say.

APOPO’s landmine research began in 1998 and the first operational trials were conducted in 2003 and 2004. Our tuberculosis detection research began in 2003 and the rats started working in 2007. For these projects it costs an average of about € 6,000 [roughly £5,175] to fully train one rat so that they are ready for surgery.

We are currently training seven for search and rescue, although they have to take turns using that one backpack!

Read more ways ingenious animals help people: