Ant Colonies Retain Memories That Outlast the Lifespans of Individuals

These algorithms are similar to the ones I developed for the computer strategy for the Empire game. They worked, but I was unable to get them good enough to reliably defeat a human player.

The first strategy I tried was simply randomness. It was pretty ineffective. A rule based one was also ineffective, as it tended to get itself into a box. But I found that adding a dose of randomness to the rule based strategy worked well.

Most computer strategies of the day cheated, or altered the rules to give an advantage to the AI. Empire didn't. I did have thoughts about creating an interface so people could provide their own AIs and then the various AIs could battle it out.

classicempire.com

There's been a lot of research on the Life game. But I bet Empire would be a much better research platform - the rules are simple, but the game play can get pretty complex. I had a lot of fun developing AI algorithms for it. I wish the ant algorithms were known at the time, I bet they'd help!

(One of the reasons the simple rules worked so well was the pieces had a hammer-paper-scissors relationship to each other.)

I just traversed the ant part of Wikipedia, and this is what I found.

> Queen ants have one of the longest life-spans of any known insect – up to 30 years.

> The fertile eggs become female worker ants and unfertilized eggs develop as males; if the fertilized eggs and pupae are well-nurtured, they potentially become queens.

> males are "quickly converted to sexual missiles."

> the queens often try to escape the males, allowing only the fastest and the fittest males to mate. Mating takes place during flight.

> One queen usually mates with several males. The sperm is stored in a special organ, known as a spermatheca, in the queen's abdomen, and lasts throughout her lifetime. This can be as long as 20 years, during which time the sperm can be used to fertilize tens of millions of eggs.

> The males have evolved for the single purpose of inseminating the queen.[3] During "the quick and violent mating," the male literally explodes his internal genitalia into the genital chamber of the queen and quickly dies.

And, moving on to army ants.

> A nest is constructed out of the living ant workers' own bodies to protect the queen and larvae, and is later deconstructed as the ants move on.

> As many as 150,000 to 700,000 worker bodies cover and protect the queen, linking legs and bodies in a mass that measures a meter across.

> In the morning, the bivouac dissolves into raiding columns that form a fan-shaped front. These raiding columns can travel up to 20 metres per hour with lead workers laying a chemical trail for other workers to follow. Smaller workers lead the column, while larger, formidable soldiers protect the flanks.

> When the queens emerge, the workers in the colony will form two 'systems' or arms in opposite directions. These queens that are hatched will move down either the arms and only two queens will succeed, one for each branch. The remaining new queens will be left in the middle and are abandoned to die.

> The whole colony of army ants can consume up to 500,000 prey animals each day, so can have a significant influence on the population, diversity, and behavior of their prey. [...] About five species hunt in higher trees, where they can attack birds and their eggs, although they focus on hunting other social insects along with their eggs and larvae.

This is a lovely article, and I feel there's a lifetime of lessons to be learned from any colony behaviour. I've recently submitted a thesis on a swarm intelligence algorithm which exhibits some of these qualities, and the parallels between the two was a core component of the contribution.

This effect, where something is globally stable, even though all the individuals that make it happen are unstable is sometimes described as "a forest whose contours remain the same, as the trees all change".

Consider this algorithm for an ant colony foraging for a good source of food (this behaviour has also been observed in ants searching for a new nest site):

  for each ant in the swarm
    if the ant is unhappy
      run to a random ant
      if the random ant is happy
        follow it to its location
      if the random ant is unhappy
        select a location at random
    if the ant is happy
      the ant continues to search its current location

   for each ant in the swarm
     the ant searches a tiny of its location, at random
     if the ant finds food
        the ant becomes happy
      if the ant doesn't find food
        the ant becomes unhappy

If you run this algorithm you will find a "clusters" of ants form, which is a number of ants who share the same foraging location. Importantly, and this is mathematically proven, the largest cluster will form in the location with the best probability for finding food. This algorithm works even when the locations change over time and, as in the article, even when the ants which found the location are replaced with ants who have simply followed other ants to get there.

The aspect which captured my attention is that there are tiny changes to individual lines of the algorithm which implement diverse behaviours such as hill climbing, optimise for exploitation or exploration, and global optimisation.

The algorithm is called Stochastic Diffusion Search and I'm in the process of polishing a Python library which implements it and its many variants for a Show HN :) The repo is here https://github.com/AndrewOwenMartin/sds some info and an explanatory animation here http://www.aomartin.co.uk/sds-animation/ and an beta version is already on PyPi here https://pypi.org/project/sds/.

Contact me (email address on my profile) if you're interested in using this algorithm or contributing to the library, it needs snappy C implementations, and a better explanatory animation!

This is an example of an "extended phenotype" as written about in https://en.wikipedia.org/wiki/The_Extended_Phenotype by Richard Dawkins (invented the word meme).

Great concept, although harder to grasp than The Selfish Gene.

It is a bit like treating the ants as stateless functions, and storing the state in the world?

I mean, I feel like the wording "retain memories" might imply a greater degree of consciousness/agency than what was actually observed. The "memory" appears to be some completely tangible phenomenon, as per their comparison of trees "retaining memory" in the form of a tree growing bark around where a branch broke off. "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." , etc. That said, it's still pretty interesting, and I think we can make some comparisons about how humans share knowledge/experience and what kind of tangible markers we use as cues for our own behaviour.

>> Apr 23, 2014 - Almost 25 years since the Iron Curtain came down, deer roaming the Czech-German border still balk at crossing areas where electric fences one lay

https://www.dailymail.co.uk/news/article-2611585/Deer-not-cr...

I also remember a story from the US. A high-security prison was removed, its razor wire fences torn down. Years later, GPS data showed an outline of the prison. The deer were still afraid of a fence that they had never themselves seen.

An interesting definition of 'memory' (and 'history') includes the 'physical record' that we can decipher.

Anthropologists study 'memories' left behind by ancient cultures that created artifacts. And the Earth keeps 'memories' of extinct animals in fossils ... and of geological events in rocks and landforms. DNA and epigenetics keep a 'memory' of lessons learned. Darwin 'remembered' evolution by the study of species.

There's a valuable lesson to be learned here ... what record will 'digitization' leave behind?

Carpenter ants built a nest in my apple tv, it took me 3 days to clear them out. I hope they don't remember it.

Fascinating. First thing that comes to mind is Family Systems theory of psychology. The idea is the family unit itself is treated as an entity that is sick, rather than any single “identified patient.” I like it because it provides a useful model for understanding transmission of observable patterns like child abuse or other behavioral problems across generations. If ants can do it for certain types of behavior, it certainly seems plausible that “human colonies” aka “families” can as well.

The book A Deepness in the Sky (https://www.amazon.com/Deepness-Sky-Zones-Thought/dp/0812536...) goes really deep (no pun intended) on this idea! I highly recommend it as some really solid sci-fi. It was full of big new ideas I had never conceived of before and often found myself sitting down just to think.

CRAB: It's too bad, Achilles, that you weren't here last week, when Dr. Anteater and Aunt Hillary were my house guests. I should have thought of having you over then.

ACHILLES: Is Aunt Hillary your aunt, Mr. Crab?

CRAB: Oh, no, she's not really anybody's aunt.

ANTEATER: But the poor dear insists that everybody should call her that, even strangers. It's just one of her many endearing quirks.

CRAB: Yes, Aunt Hillary is quite eccentric, but such a merry old soul. It's a shame I didn't have you over to meet her last week.

ANTEATER: She's certainly one of the best-educated ant colonies I have ever had the good fortune to know. The two of us have spent many a long evening in conversation on the widest range of topics.

ACHILLES: I thought anteaters were devourers of ants, not patrons of ant-intellectualism!

ANTEATER: Well, of course the two are not mutually inconsistent. I am on the best of terms with ant colonies. It's just ants that I eat, not colonies-and that is good for both parties: me, and the colony.

- Douglas Hofstatder, "Godel, Escher and Bach"

Doesn't almost every community of living creatures retain memories that outlast the lifespans of individuals?

Nice article. It’s fascinating how the experiences of individuals can shape the behaviour of the colony in future. (I am interested in studying this in future.) I think the ants as simple input and output devices i.e. provide stimulus, get some results. But, the interaction of ants provides the output to the complex situations.

When one observes the colony while doing any colony related function, one can see how each individual is assigned with specific function e.g. foraging, nursing etc. And suppose if you remove these ants, there will be a new set of individuals doing that function. Somewhat similar to the neurons of brain. (One has to compare the extent of similarities.)

PS: I used to do research with ants. My master’s thesis was on colony cohesion. What are the factors important for the cohesion? I have looked at few aspects (physical) of this.

Is it surprising? We do the same and call this culture. A set of behaviour rules that we inherit from previous generations, don't really need to understand but can still use it to increase our survival and which slowly adapts to big time environment changes.

This reminds me of the parable of the 5 monkeys: http://wiki.c2.com/?TheFiveMonkeys

This isnt very surprising me considering we humans--and probably most other living species--are pretty good at this. Memory seems to be an emergent property of a network.

Reminds me of this:

https://skeptics.stackexchange.com/questions/6828/was-the-ex...

I’ve heard the concept of a “hive mind” before but this is extraordinary.

So basically it's a massively legged delay line memory

ants have culture, ants have memes.

culture