But they are actually following a colony algorithm rather than making individual decisions, as Eric Cassell discusses in Animal Algorithms: Evolution and the Mysterious Origin of Ingenious Instincts (2021):
Ant behavior specialist Elva Robinson offers an example of how the hive mind works: The colony’s survival depends in part on fat stored in ants’ bodies and the younger ants are the fatter ones. They stay in the colony and look after the eggs, larvae, and pupae — also guarding the fat. The older ants, who go out to forage, are leaner (and perhaps therefore hungry). They also have shorter expected life spans so overall, their greatly increased risk of dying outside the nest is less of a loss to the colony. They bring back food but mainly give it to the fatter, protected ants, remaining lean themselves. Robinson comments:News, “The hive mind: Leafcutter ants behave like farmhands but… ” at Mind Matters News (June 3, 2022)
These ants are great examples of self-organisation because each ant is making a decision based only on the information that it has about itself. It doesn’t have to know the overall system of the colony and that’s quite an important lesson for lots of human systems where we tend to focus a lot on centralised control where you have one control centre collecting all the information and deciding what to do. But obviously, if there’s a problem with that control centre then your whole system will break down. For ants, decisions are processed in a very distributed way, so all the individuals contribute. And if any one individual is taken out of the system, it will still work. So in the case of our experiment, if some ants were removed as we did in our experiment, then the next leanest ants will go out. And if you keep on removing ants then more and more corpulent ants — more fat ants — will start to go outside. So it’s all very self regulating.Elva Robinson, “The Hive Mind — How Ants Know Their Place” at The Naked Scientists (June 6, 2010)
Takehome: Ants’ complex behavior patterns are part of following a colony algorithm rather than making individual decisions. They make immediate individual decisions but the hive mind of the colony makes the big ones. We humans struggle to understand the hive mind because our world is one of uniquely individual minds that can, with effort, be got to work together — for a while.
You may also wish to read: Do ants think? Yes, they do — but they think like computers . Computer programmers have adapted some ant problem-solving methods to software programs (but without the need for complex chemical scents). Navigation expert Eric Cassell points out that algorithms have made the ant one of the most successful insects ever, both in numbers and complexity.
How do insects use their very small brains to think clearly? How do they engage in complex behaviour with only 100,000 to a million neurons? Researchers are finding that insects have a number of strategies for making the most of comparatively few neurons to enable complex behavior.