Trails in the Sky, Cyborgs, & Empathy
The Most Intelligent Animal is the One That Avoids Extinction
Since vision is our most valuable sense, we might presume that it is the most important sense for other animals as well. That is not the case for a lot of animals including dogs and honey bees. Their primary sense is smell. Honey bees are legally blind (by our standards) but their sense of smell is superior to many dogs: sensitivity is measured in low parts-per-trillion. Like dogs, honey bees can find buried land mines. But they can do it without risk of setting the mines off (1).
Researchers/beekeepers train bees to locate land mines at Sandia National Laboratories. Image courtesy of Sandia National Laboratories, reproduced with permission.
Each honey bee has its own signature colony smell. Guard bees recognize robber bees from other hives (yes, that is a thing bees do during nectar scarcity) by their alien smell. Airborne hormones or pheromones are how 60,000 bees coordinate tasks and spread warnings. But smell is also how honey bees find flowers. If the wind is blowing just right, a floral plume from a patch of flowers provides an airborne trail that honey bees can follow.
Not all foragers are directed toward nectar sources by watching their sister foragers dance. Someone has to discover new sources of nectar and pollen because flowers continuously come into bloom and go out of bloom. Bees scout for new patches of flowers by leaving the hive and flying in increasingly larger spirals (see figure below) until they smell a forage flower. The foraging bee will then switch from a spiral pattern to a zigzag flight pattern that keeps her in the leeward odor plume of the forage source. She casts about, left and right, until she arrives at the source. Once she has collected her fill of nectar or pollen, she will beeline back to the hive. Return flights will simply retrace that beeline path. If she dances for recruits, they will also retrace her beeline path. In this way, recruited flights are much more energy efficient than scouting flights. This is just one example of how social bees are much more efficient in a task than solitary bees (the vast majority of the 20,000 species of bee).
Illustration by the author.
The following is a short aside. I don’t get many opportunities to share stories that combine multirotors with insect biology. The following describes a cybernetic organism or cyborg--a combination of living organism and machine. Melanie Anderson, a doctoral student of mechanical engineering at the University of Washington hooked a living moth antenna (the insect’s natural sensor for smell) to a pre-amplifier and threshold detector to indicate if a smell is present or not. It then mounted it on a tiny quadcopter that modified its flight based on whether or not it was within an odor plume. (2)
Click here to view a video of the 'Smellicopter'
Unfortunately, the Smellcopter currently senses the concentration of all smells and does not differentiate between smells like insects. The multirotor is a Crazyflie, a tiny, popular, and inexpensive quadcopter that is used in a lot of multirotor experiments. I can imagine applications for this flying cyborg in search-and-rescue, mine clearing, crop health monitoring, pollution detection, drug enforcement, and gas leak detection.
There is a point to this note on honey bee olfaction: non-human animals experience an entirely different reality than we do. Compared to a honey bee, we are perceptually deprived in smell, taste, touch, and sense of electrostatic and magnetic fields. Although honey bees have a much lower visual acuity than we do, they can see patterns in flowers ("nectar guides") that are invisible to us because we do not sense ultraviolet. And they have an additional visual sense we lack entirely. It is a visual sense in addition to color hue, color saturation, and brightness: honey bees can visualize the polarization (direction and magnitude) of light. This tells them where the sun is (for navigation) even when the sun is obscured by clouds.
We should be in awe of the honey bee and other animals. We should not try to empathize with them because we can never know what it is like to be a honey bee or a bat (to quote Thomas Nagel, see footnote 3). Cognition is nature's way of adapting to change. Cognition is fed by the senses and the senses of non-human animals are beyond our ability to comprehend except at a very abstract, symbolic level. One specie's cognitive ability is not greater or less than another specie's cognitive ability because each specie's cognition is adapted to a uniquely sensed environment (umwelt) and survival needs. Otherwise, the species becomes extinct.
Most species that ever lived are now extinct. The average species "lifespan" of mammals from origination to extinction is about 1 million years. Some mammal species have persisted for as long as 10 million years. The honey bee has been on this earth for roughly 120 million years. It has survived multiple mass extinction events. Homo sapiens has existed on this earth for less than 350 thousand years - a shorter period than all other Homo lineages. Only time will tell which specie did a better job at avoiding extinction.
(1) “Sandia, University of Montana researchers try training bees to find buried landmines”, press release by Sandia Labs, April 27, 1999. Retrieved 11/4/2018, https://www.sandia.gov/media/minebees.htm
Gaidos, S. (2008), Sting operation: Scientists use bees and wasps to sniff out the illicit and the dangerous. Sci News, 174: 16-19. doi:10.1002/scin.2008.5591740717
'Sniffer bees' reared to detect landmines in Balkans, The Telegraph, May 23, 2014, https://www.telegraph.co.uk/news/worldnews/europe/bosnia/10852715/Sniffer-bees-reared-to-detectlandmines-in-Balkans.html
Joseph Shaw, Nathan Seldomridge, Dustin Dunkle, Paul Nugent, Lee Spangler, Jerry Bromenshenk, Colin Henderson, James Churnside, James Wilson, Polarization lidar measurements of honey bees in flight for locating land mines. Opt Express. 2005 Jul 25; 13(15): 5853–5863.
Melanie J Anderson et al 2020 Bioinspir. Biomim. 16 026002
(3) Nagel, Thomas (1974). "What Is It Like to Be a Bat?". The Philosophical Review. 83 (4): 435–450. doi:10.2307/2183914. JSTOR 2183914.
A good summary Thomas Nagel's paper can be found at Wikipedia.