Richard Feynman’s Nontoxic Ant Ferry

June 2, 2010

RICHARD FEYNMAN, CALTECH’S Nobel Prize winning physicist (1965; quantum electrodynamics), was a Princeton University graduate student during the early years of World War II when foraging ants crawled in his bay window and spurred development of an ant control device that did not kill the creatures. It was not quite as momentous as the proverbial apple conking Isaac Newton on the head in 1666 and waking him up to gravity. But according to, Feynman’s “analysis of the behavior of ants involves some of the same ideas that were central to his work in theoretical physics.”

On a more mundane note, Feynman recounts the experience in his 1985 book, Surely You’re Joking, Mr. Feynman!: “In Princeton the ants found my larder, where I had jelly and bread and stuff, which was quite a distance from the window. A long line of ants marched along the floor across the living room. It was during the time I was doing these experiments on ants, so I thought to myself, ‘What can I do to stop them from coming to my larder without killing any ants? No poison; you gotta be humane to the ants!'”

Interesting sentiments coming from a man who worked on the Manhattan Project in New Mexico to help develop atomic energy into the bombs dropped on Japan to end World War II. But, of course, the goal of the Manhattan Project was to build the bomb ahead of Hitler’s scientists working in Europe. Peace and freedom were envisioned at the end of the atomic trail.

“One question that I wondered about was why the ant trails look so straight and nice,” wrote Feynman in his oft-reprinted 1985 book. “The ants look as if they know what they’re doing, as if they have a good sense of geometry. Yet the experiments that I did to try to demonstrate their sense of geometry didn’t work. Many years later, when I was at Caltech and lived in a little house on Alameda Street, some ants came out around the bathtub. I thought, ‘This is a great opportunity.’ I put some sugar on the other end of the bathtub, and sat there the whole afternoon until an ant finally found the sugar. It’s only a question of patience.”

Today we know that ants are putting down a pheromone trail, and that over time the trails most frequented (i.e with food at the end) get a stronger dose of pheromone while the pheromone disappears from the least-wandered trails. Feynman’s observations are called Ant Logic or Ant Colony Optimization by those who, in or out of the bathtub, today study the trail-following process, oftentimes using virtual ants in computer simulations for Internet routing, robotics, and business and travel solutions.

Apparently, via pheromone trails between their nest and food resources, in their everyday life ants have mastered a workable solution to what is called The Traveling Salesman Problem, which the web site of the same name (abbrev. TSP) calls “one of the most intensively studied problems in computational mathematics.”

Planning the best route between a hundred cities for a traveling rock band or the quickest path for sending data packets among thousands of Internet nodes on the Worldwide Web can apparently overheat and exhaust modern computers. In a chapter titled “Ant Logic” in The Perfect Swarm, book author Len Fisher says: “To calculate the optimal route that Ulysses might have taken between the 16 cities mentioned in The Odyssey, for example, requires the evaluation of 653,837,184,000 possible routes.” That works out to “ten thousand billion calculations” for a relatively simple travel problem.

Fortunately, Nobel Prize-caliber calculations were not needed to disrupt ant trails and humanely protect Feynman’s Princeton larder or Pasadena home. ANT FERRY was the name Feynman gave to his least-toxic ant removal device: “I made a lot of little strips of paper and put a fold in them, so I could pick up ants and ferry them from one place to another,” wrote Feynman in Surely You’re Joking, Mr. Feynman!.

“What I did was this: In preparation, I put a bit of sugar about 6 or 8 inches from their entry point into the room, that they didn’t know about. Then I made those ferry things again, and whenever an ant returning with food walked onto my little ferry, I’d carry him over and put him on the sugar. Any ant coming toward the larder that walked onto a ferry I also carried over to the sugar. Eventually the ants found their way from the sugar to their hole, so this new trail was being doubly reinforced, while the old trail was being used less and less. I knew that after half an hour or so the old trail would dry up, and in an hour they were out of my larder. I didn’t wash the floor. I didn’t do anything but ferry ants.”

No Nobel Prize is needed to obliterate ant trails and naturally protect larders without toxins or even killing any ants. However, the patience, the extra hour, may be outside the modern mindset. Nonetheless, thank you Mr. Feynman for what your colleagues call a PROOF of CONCEPT.

Beneficial Bugs Challenge Theoretical Physics

November 8, 2009

INSECTS, MICROBES, PLANTS and other organisms form complex ecological systems with all sorts of synergisms, antagonisms and cooperative interactions, leading oftentimes to beneficial insects controlling what we consider pests. Whether it be forest, desert, farm field or garden, intricate and nuanced ecological communities can be nurtured to provide a measure of “natural” biological pest control.

The nuanced complexity of biological and ecological systems has at times intrigued theoretical physicists usually more attuned to quarks, neutrinos, chaos theory and quantum phenomena. Murray Gell-Mann, winner of the 1969 physics Nobel Prize as a Caltech (Pasadena, California) professor “for his contributions and discoveries concerning the classification of elementary particles and their interactions,” created the Santa Fe Institute (New Mexico) to better focus on “the theory of complex adaptive systems.”

Humans, plants and animals are individually and collectively at the ecosystem level examples of complex adaptive systems. Which is one reason creating sustainable agriculture is such a challenge, and companies such as Rincon-Vitova Insectaries end up with catalogs of 55 pages of beneficial insects, microbes, seeds, traps and other inputs for creating sustainable garden and farm systems. And even then, it is not always easy and can take longer than expected to force changes in even the smallest complex adaptive system that is a backyard garden.

“Unfortunately, it will be a long time before human knowledge, understanding, and ingenuity can match–if ever they do–the “cleverness” of several billion years of biological evolution,” wrote Gell-Mann in his book, The Quark and the Jaguar. “Not only have individual organisms evolved their own special, intricate patterns and ways of life, but the interactions of huge numbers of species in ecological communities have undergone delicate mutual adjustments over long periods of time.”