Welcome to the honey bee college for explosives detection! This is a real thing,
and you’re about to witness, step-by-step, how these honey bees are collected, qualified,
trained, and finally transformed from mere pollen collectors into explosive detection specialists.
The journey begins when the honey bees are first drafted from their hive.
With the help of a specially designed handheld device,
the bees are safely collected inside a chamber before being transferred to the lab.
Before training starts, these honey bees need to chill!
The bees are cooled to slow down their movements for handling purposes. The chilled bees are then
safely placed into their harness, and left for 30 minutes to get used to their new environment.
But loading each bee manually into a harness is kind of a tedious task for a technician.
This is why some labs, like the Visual Communications Unit at Rothamsted Research,
came up with an automated bee loading machine. The bees are confined, so they are forced to walk
into a cylinder one by one. Each cylinder is then dropped into the loading tube,
where each bee is slowly and safely pushed into the harness and then placed into position.
The bees are typically kept in the harness for a few days before being released back to the hive.
But how do you train honey bees, exactly?
Honey bees are amazing at detecting chemicals in the air. That’s how they can find their favorite
flowers. The simple steps required to condition a dog also apply to bees. You present the animal
with a neutral stimulus, say the ringing of a bell, which doesn’t mean anything at first.
But if you follow the bell ring with the delivery of a biologically significant outcome, like food,
the animal quickly learns that the ringing of the bell means food is coming soon. From that point
on, the dog starts salivating in anticipation that food is coming, everytime it hears the bell ring.
If you replace the bell ring with the smell of narcotics, the dog will salivate everytime it
smells that particular narcotic. This is the basic principle behind training a sniffer dog.
Honey bees may not salivate like dogs, but they do have a tongue, or proboscis, which
they exclusively use for eating. In addition, the antennae of a honey bee are vapor sensors
with the sensitivity thresholds of parts in trillion, similar to the sense of smell of a dog.
Since the honey bees are randomly collected, there is one important qualification test that the bees
need to pass before being trained, and that is the ability to stick out their tongue when
presented with sugar water on the tip of a swab. This is called Proboscis Extension Reflex or PER.
The bees that can PER make it to the training round.
While the bees are given a 6-second exposure to an explosive vapor,
they are given a sugar water reward during the last 3 seconds.
The training phase can also be automated where the vapor is released followed by
a feeding mechanism rising in front of the bees, so they associate the two together.
After 4 rounds of training, the bees that PER voluntarily after receiving
the explosive scent, are ready for field work.
But aside from visually looking at the bees, how do you exactly monitor their response?
There are two ways to do this: One is with the help of a camera.
The bees are placed onto a platform which is then loaded into a monitoring device.
The camera inside the device records the bees up close.
With the help of some computer vision algorithms, the camera output can be interpreted to know when
the bees PER A unanimous PER signal from all the bees point to a high likelihood that they
have detected the particular type of explosive that they were trained on.
The second way of monitoring also involves a cartridge of bees being loaded into a machine,
but instead of a camera, there is an infrared LED in front of each bee.
The infrared light hits the bee and then bounces onto a light sensor. Based on the
amount of light picked up by the sensor, it can tell if the bee had its tongue out or not.
Now for the real test. 6 cartridges are loaded into a handheld detection device.
Each cartridge has 6 honey bees on it. Note the infrared light in front of each bee.
A monitoring screen shows 36 green squares, each representing a bee that has not yet responded.
To test an air sample, the handheld detector is held in proximity to the target,
and with a push of a button, all 36 bees are exposed to air in the bag for 6 seconds.
If a bee extends its tongue, the corresponding square turns from green to red.
What’s cool is that the bees in each cartridge could be trained on a different substance,
so the device could detect, not only the presence, but also the type of substance.
After a few days, the bees are released back to the hive.
It takes months to train a sniffer dog, but honey bees, you can train them in a few hours.
The maintenance cost of bees is also a lot less than dogs. You just need some sugar water.
But more importantly, there are certain applications where bees may be a better
fit than dogs, say for detecting landmines. It is not impossible for the weight of a dog
to trigger a landmine. The African Giant Pouched Rats are typically used for sniffing landmines,
since they are effective and only weigh a couple of pounds.
Even though bees can be trained to detect land mines, researchers soon realized that walking
across a minefield with a handheld detector to see where the bees stick out their tongue wasn’t
the best idea. So instead, they released the bees and used drones to monitor them. The trained bees
tend to cluster around places where mines are buried, in the hopes of finding food. Analyzing
the footage captured by the drones, could reveal where landmines may be hidden in the ground.
But not all animals are trained to help with detecting explosives. Some were trained to deliver
them. Many are familiar with the anti-tank dogs that the Soviets trained in the 1940s,
to deliver bombs to German tanks during WWII. But have you heard of the pigeon-guided bombs?
Just like dogs and bees, pigeons can be conditioned to respond to a particular
stimulus. Say scoring in ping pong means the little feeder opens up so the pigeon can eat. But
how do you take a pigeon from playing ping pong, to guiding a bomb? Turns out, in 3 easy steps!
It starts with a simple moving circle. The pigeons soon learned that pecking the circle means getting
a reward in the form of food. After some time, the circle was replaced with a moving metal window.
The pigeon also got a metal beak, which was connected to a wire.
This would help determine the exact point of contact on the moving metal window.
After continuing to peck at the center of the window, the pigeon would be rewarded.
And finally, the bird was presented with the image of a warship.
The pecking location on the image was used as an input into the guidance system of the glider bomb,
where the pigeon would be in. Whenever the bomb would start to go off-track, the picture of the
target would move from the center to the edge of the screen, but the trained pigeons would
continuously peck at the center of the target, which would bring the bomb back on-track.
The American psychologist and behaviorist, B. F. Skinner, who was behind this project,
eventually lost funding since no one took his project seriously.
The optics of having a bomb guided by a bird wasn’t too good either.
But using birds as a type of weapon is not limited to the military.
The Dutch police trained eagles to intercept unknown drones. From a young age, the eaglets
would be trained to see the drones as prey. As adults, eagles would intercept the drones using
their hunting instinct, and take their prey down to a safe place, waiting to be rewarded with food!
Even though the Dutch police reported a 95% success rate with these eagles,
animal rights activists were not too happy and shut down the program.
That’s despite the fact that Teflon gloves were being developed for eagle claws to
prevent injuries by fast rotating drone propellers, which are extremely dangerous.
The fact of the matter is that animals have been employed by armed forces of many countries
to perform specific tasks. Falcons are used in some air bases in Lithuania to scare away birds.
Foreign Object Damage is a real hazard to airplanes.
Dolphins and sea lions are trained to detect and mark underwater mines to protect the navies
around the world. They can even attach a hook to underwater objects and help retrieve them.
That includes a late 19th century steam-powered torpedo,
which was detected by a dolphin and now sits in a museum.
In some cases, technological alternatives are available. Instead of eagles, we could use
drones that take down other drones, either by physical contact, or by throwing a net at them
to neutralize the propellers. Animals may be put in harm's way during military operations,
and their treatment and care can be challenging in a combat environment.
This is why the decision to use animals in the armed forces is a complex one
that must consider both the potential benefits and the ethical considerations.