Kill Decision(54)

“A single weaver colony might span dozens of trees and include hundreds of nests built throughout their territory in an integrated network. From here they launch attacks, raise young, and care for livestock, other insects that they raise for nectar.”

The team members looked surprised at this last part.

McKinney drew another series of points similar to the Traveling Salesman Problem and started connecting them. “Weavers maintain a flexible network of routes between their population centers. And unlike most ants, they have excellent vision. They also have better memories than regimented species such as army ants. Individual weaver ants can accrue ‘experience’ which informs later actions.”

Expert Five piped in. “So they’re like a neural network.”

McKinney nodded. “Precisely. Weavers process experience via mushroom bodies. . . .” She drew the outline of an ant’s head, inside of which she drew several large blobs. The largest, occupying the bottom center, she shaded in. “These are brain structures found in almost all insects, and they manage context-dependent learning and memory processes. Their size correlates with the degree of a species’ level of social organization. The larger the mushroom body in the brain, the more socially organized an insect society is. As we’d expect, weaver ants have an unusually large mushroom body, which endows weaver workers with above average memory.

“That memory sharpens the iterative component of weaver swarming intelligence. Because swarming intelligence is all about data exchange. What we call”—she wrote a word on the board—“stigmergy. Stigmergy is where individual parts of a system communicate indirectly by modifying the local environment. In the case of weaver ants, they exchange data mostly through pheromones.” She started drawing lines that represented ant paths. “If they encounter a source of food or an enemy, they return to the nearest nest, all the while laying down a specific mix of chemical pheromones in a trail that communicates both what they’ve encountered—food or threat—and the degree to which they encountered it—lots of food or a big threat. Half a million individual agents moving about simultaneously doing this creates a network of these trails, known as the colony’s pheromone matrix, holding dozens of different encoded messages. This matrix fades over time, which means it represents in effect the colony’s current knowledge. As weavers encounter these trails, they’re recruited to address whatever message the trail communicates—for example, to harvest food or fight intruders. As they move along the trail, they reinforce the chemical message—sort of like upvoting something on Reddit or ‘Liking’ someone’s Facebook status. As that pheromone message gets stronger, it recruits still more workers to the cause, and soon, clusters of ants begin to form at the site of the threat or opportunity.”

Expert Two, the blond man, nodded. “Meaning it goes viral.”

McKinney nodded. “Basically, yes. In this way, weavers manage everything from nest building, food collection, colony defense, and so on. At each iteration of their activity, each ant builds a solution by applying a constructive procedure that uses the common memory of the colony—that is, the pheromone matrix. So, although individual weaver ants have very little processing power, collectively they perform complex management feats.”

McKinney dropped the marker in the tray at the base of the whiteboard. “In fact, if I were going to create an autonomous drone—and I had no ethical constraints—swarming intelligence would be a logical choice. Lots of simple computational agents reacting to each other via stigmergic processes. That’s why weaver ants don’t need a large brain to solve complex puzzles. They can solve problems because they can afford to try every solution at random until they discover one that works. A creature with a single body can’t do that. A mistake could mean biological death. But the death of hundreds of workers to a colony numbering in the hundreds of thousands is irrelevant. In fact, the colony is the real organism, not the individual.”

Expert Five interjected, “Then we would expect swarming drones to be cheap and disposable.”

McKinney nodded. “And individually, not very smart. The demise of one or dozens or hundreds might not mean the demise of the group—and the survivors would be informed by the experience of swarm mates around them.”

Singleton scribbled on his notepad. “You sound intrigued by the possibilities.”

“I find weaver ants fascinating. But I wouldn’t want to meet them scaled up in size and given weapons. It would be an insanely foolish thing to build.”