An ant colony has memories its individual members don’t have (2019)

> Ants use the rate at which they meet and smell other ants, or the chemicals deposited by other ants, to decide what to do next. A neuron uses the rate at which it is stimulated by other neurons to decide whether to fire. In both cases, memory arises from changes in how ants or neurons connect and stimulate each other.

Main takeaway, very interesting analogy. Ant colonies are great examples of complex systems with emergent large-scale behavior. Indeed the same could be said about networks of neurons. Interesting to think of an ant colony as the sum of oscillations of signals.

> Every morning, the shape of the colony’s foraging area changes, like an amoeba that expands and contracts.

Sounds like an emergent macroscopic "heartbeat" of the colony.

> In an older, larger colony, each ant has more ants to meet than in a younger, smaller one, and the outcome is a more stable dynamic.

It makes sense that small perturbations would temporarily morph the heartbeat, but would probably snap back into the default oscillation pretty quickly. It would be interesting to see if a small colony is equally resilient to small perturbations as a large colony is to large perturbations, keeping some adjusted ratio of the perturbationSize/colonySize constant.

> individual ants live at most a year.

This comes as a surprise to me.

Reminds me of the "Tradition is smarter than you are" article that was posted here a few days ago.

http://scholars-stage.blogspot.com/2018/08/tradition-is-smar...

We are all colonies of creatures, really interesting book written 100 years ago called the "Soul of the Ant" by https://en.wikipedia.org/wiki/Eug%C3%A8ne_Marais

> Foraging in a harvester ant colony requires some individual ant memory. The ants search for scattered seeds and do not use pheromone signals [...]

This was surprising to me. Until now, I was under the impression that all ants used pheromones, which leads to coordination not with each other but through the environment [1].

[1] https://en.wikipedia.org/wiki/Stigmergy

For a sci-fi take on this, Children of Time and Children of Ruin, Adrian Tchaikovsky