Wow – my first post. This is nerve-wracking in a here-I-go-putting-myself-out there-please-oh-please-like-me kind of way. Here goes nothing!
In case you weren’t aware, honeybees are about the coolest little creatures out there. Admittedly, as a child I was TERRIFIED of anything with a stinger…ask the stranger who almost fell off his bike and over the bridge after I screamed bloody murder when a bee landed on me…sorry man. BUT now that I’m all grown-up and matured (ahem…) I have come to appreciate the little guys, and I have science to thank for that.
Honeybees are classified as a eusocial insect, meaning they have reached the highest level of social organization. Their society consists of a queen, drones (all males whose only purpose is to mate with the queen, after which he dies), and worker bees (all females) who go through a sequence of duties in their lifetime: housekeeper, nursemaid, construction worker, grocer, undertaker, guard, and finally, after 21 days they become a forager, searching for food. [Insert your choice of gender role-related joke here].
I think foragers are just the most amazing little guys…uh, gals. Upon finding a food source, they return to the hive and must communicate to the other foragers where to find said food. In order to do this they perform 1 of 2 dances, a “round” dance or a “waggle” dance (giggle). The round dance is performed if the food source is less than ~50m away. The waggle dance is performed if the food source is a longer distance away. Since the foragers must travel further to find these far away sources, they require more information – just how far away is it? which direction? These details are actually incorporated into the waggle dance. The duration of the dance indicates the distance to the food source, while the angle the dance is performed at represents the direction to the food source relative to the sun – AND the bees can even correct for the changing position of the sun!! AMAZING, no? Check out this video yanked from you-tube to see the waggle dance.
Just when you thought they couldn’t get any better, turns out honeybees can actually be trained to sniff out unexploded landmines…yes, you read that correctly…read on.
First a little background. Unexploded ordnance devices (UXOs), better known as landmines, obviously result in humanitarian crises, not only due to the number of people who are killed or injured, but also due to the loss of agricultural land. Therefore, research into how these devices can be safely detected and removed is ongoing.
Currently, landmines can be detected by using handheld metal detectors, however, since these require a person to operate them, this is obviously not a preferred method. Another method of detection is the use of dogs trained to detect the scent of chemicals associated with the landmines. Again, this method requires a human handler, putting both the handler and the dog at high risk.
Researchers out of Montana State University and the University of Montana have developed an amazing detection technique that would avoid the need to put humans or other animals at risk. ENTER THE HONEYBEES. These researchers have actually trained honeybees to detect a specific chemical (called 2.4 DNT) associated with landmines. The bees are first conditioned to the chemical by providing a feeder nearby the honeybee hive that is pumped with syrup (jackpot for the bees!) which contains the scent of the DNT. Very quickly, the bees associate this smell with a rich food source. The feeders are then moved further away from the hive, forcing the bees to search out and forage for the food reward. Finally, many feeders are placed are placed at long distances from the hive, only some of which are pumped with the scented syrup. This requires the bees to search even further and distinguish between feeders for the reward. Ultimately, the bees will spend greater periods of time where the chemical scent of the DNT is the strongest, which will presumably be where the landmines are located. By using a fancy-schmancy detector called a scanning lidar instrument, a spatial map of honeybee densities can then be developed, in turn mapping where landmines are present.
The scanning lidar instrument was improved numerous times until it was able to distinguish between moving vegetation and honeybee densities. Field experiments successfully showed that the instrument can correctly detect densities of honeybees indicating the presence of the DNT chemical. While improvements to the instrument are still required, such as refinement to provide even finer differentiation between moving vegetation and honeybee densities, changes to allow a stronger signal to be elicited from the bees, and presets implemented in order to automatically adjust for weather conditions, these findings are certainly promising.
While, of course, questions remain, (ie. what happens when the bees eventually realize the scent of DNT does not always mean food? how long after training can mapping the bees be considered accurate?) overall, the brilliance of the honeybees is matched by the scientists in this case. By using the natural ability of the honeybee to forage for desirable food sources, it may be possible to save tens of thousands of lives each year. The ingenuity in marrying the complex physical and engineering feat of the detection instrument (not to mention the processing of all the data collected) with a naturally occurring biological phenomenon is truly astounding. Can’t wait to see where this research goes!
(Reference: Carlsten ES et al. Applied Optics, 2011:15;2112-2123.)