Ants compete, recruit to identify best colony (w/ Video)

Nov 04, 2010
Temnothorax ants are marked for a research experiment. These ant colonies are small enough that all workers can be individually marked, and they thrive in glass-walled nests that allow detailed video analysis of every social interaction.

(PhysOrg.com) -- Professor Stephen Pratt studies how small ant colonies pick a new nest when theirs is destroyed or is no longer viable, and has found that the "brain" of the colony is distributed throughout the group of workers.

Ants have amazed, and annoyed us, for decades. They invade our homes and gardens, but they also manage to choose and build tightly structured colonies using a group mentality that nearly mimics humans.

How do they do this? Through what’s called collective intelligence.


The video above shows a group of Aphaenogaster cockerelli workers engaging in collective retrieval. These are unusually effective at cooperating to retrieve food items too large for a single ant. To learn how they do this, ASU researchers designed this artificial food item and made it attractive by smearing it with fig paste. The forces exerted by each ant can potentially be measured through the deflections of the sensor arms.

Stephen Pratt, a core faculty member of Arizona State University’s Center for Social Dynamics and Complexity, a member of ASU’s Consortium for Biosocial Complex Systems, studies how small (roughly 200) ant colonies pick a new nest, or home, when theirs is destroyed or is no longer viable. He found that the “brain” of the colony is distributed throughout the group of workers, and that there is no one ant doing the thinking or making the decisions for all of them.

Pratt said that ant colonies do have a “queen” ant, but she is mostly the reproductive system for the colony.

“Ants have to reach a consensus if they want to move the colony to a different location,” said Pratt, an associate professor at the School of Life Sciences in the College of Liberal Arts and Sciences. “There are a few key ingredients to how they do this. The main thing is that they have to communicate, and that communication has to say something about how good a site it is.”

According to Pratt, colonies show strong preferences for important nest attributes and can pick the best of several sites, even when few ants visit more than one site.

His research shows that the decision emerges from recruitment at each site, organized by a minority of active “scout” ants. When one of these ants find a site, the decision to bring nestmates there depends on how good the ant thinks it is, a simple rule that leads to stronger recruitment at better sites.

In a sense, he added, there is a “snowball effect.”

“There is a competition going on here,” he said. “There are some ants advertising one site and other ants advertising another. The number of ants visiting and advertising is rapidly growing for the good site. The ants essentially ‘vote’ based on the number of ants visiting a site. If the site reaches a quorum, or threshold, they increase the advertising and basically make a higher level of commitment to that site.”

He added that while the subset of ants are out recruiting nest sites the rest of the colony is at the old nest waiting to be carried to the new site… literally. Once a quorum is reached on a new site, the ants who founded or are advertising the new site head back to the old nest and start to physically carry ants, like the passive ants, the queen and young ants, to their new home.

In addition to his study on collective intelligence, Pratt also researches how the size of an affects decision performance; whether ant colonies show ‘personalities;’ and if colonies make rational decisions.

Pratt said the division of labor, quorums, positive feedback and communication that allow an ant colony to make a decision without a leader are all features you find in many other complex adaptive systems, such as human social systems, nervous systems and ecosystems.

To further his research, he is working with engineers to build an ant robot that can be used to manipulate communication within actual colonies to recruit ants to new sites. Pratt is also in the process of developing ways to better observe the hundreds of ants in a colony by using computer vision tools, and he is starting to incorporate ideas from psychology and economics to the study of ant colonies.

Pratt said, “If an ant colony is one ‘,’ we should be able to take methods from these fields to study and understand how a colony thinks, which I am focusing on right now.”

Explore further: Better focus at the micro world: A low-budget focus stacking system for mass digitization

More information: www.public.asu.edu/~spratt1/index.html

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User comments : 8

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jsa09
5 / 5 (1) Nov 04, 2010
I think the human brain works a lot like a colony instead of a colony working a lot like a brain. We seem to internalise but many parts of our brain take a vote and come to a consensus. People are indecisive when they cannot come to a consensus within their own mind possible have a faulty system of evaluation. When a human comes to snap decisions easily and often it may also be a disproportionate system of evaluation - something that is built in to the brain. We can see that many people have the internal argument inside their heads trying to come to a method of picking between options when there is no clear winner. This same decision making process is often depicted in cartoons with little images discussing options while the proper character sits there indecisive.
Ravenrant
5 / 5 (2) Nov 05, 2010
Ants are amazing, the larger the group the smarter they get. Just the opposite of us.
Honor
not rated yet Nov 05, 2010
wow, pretty amazing. i always had the idea that ant colonies were actually a single creature, sorta like multi-cell organism.
ArtflDgr
1 / 5 (1) Nov 05, 2010
Turns out that collectivisms model is made up of individuals…

That ant colonies which we assume is a collective.
Turns out to be individual based distributed computational..

Like human free market (capitalist) societies!!!

He found that the “brain” of the colony is distributed throughout the group of workers,
and that there is no one ant doing the thinking or making the decisions for all of them.

They have leaders… but their leaders don’t lead.. they just produce workers
So the king or queen is not a king or queen!!!

It’s a breeder slave to the colony, a servant of the society of individuals.
ArtflDgr
not rated yet Nov 05, 2010
Comment:Ants are amazing, the larger the group the smarter they get. Just the opposite of us.

Answer: really?

You mean small tribes of humans who can only do what their masters tell them who rule a collective
Can invent space flight, computers, telephone systems and battleships, and self organize and self adapt fast to changing situations?

or the larger we get with independent actors allowed to act on their own, like ants, we get smarter too...

you just been told we are dumb so long by people who want you to think they are smarter so they can rule that you believe it, and don’t believe what was known before.

At what point would a common person realize that 300 million distributed computational machines would beat out 10,000 limited processing adjuncts under a single person or committee (a soviet is a committee) computing the answers too slow to even have time to even think about them?

The whole time they are imagining that they are making the efficient collective like ants,
ArtflDgr
not rated yet Nov 05, 2010
The whole time they are imagining that they are making the efficient collective like ants, but in truth we are making a singular thinking entity with a distributive body which some aristocratic types want to be the brains

And that is not a functional society...

A society is a collection of distributive computation entities: individuals...

A society is not one computational entities ideas distributed to be copied by the
collection of unthinking adjuncts as the distributive thought of one, to many.

Turns out their masters and kings and queens are just breeder cows they depend on so that they can be free as individuals to not have to worry about mating or sex…

they are their own masters, and the king and queen are slaves.

They have the same kind of organization we have been moving away from!!
migmigmig
5 / 5 (1) Nov 06, 2010
@Honor:

Worker ants are actually sterile haploid clones of the queen, with only one copy of chromosomes instead of the normal two that diploid animals have.

Essentially, from a genetic perspective, an ant colony is one enormous female organism plus a few little male drones.

This makes evolutionary sense -- it would be bad for individuals to give up their chance to pass along their genetics, unless their genetics were identical to the individual who continues to reproduce.
Ravenrant
not rated yet Nov 07, 2010
to ArtflDgr,
If there are 5 people attending a soccer match or football game what are the chances they will riot? Small villages in rain forests live WITH the forest, the large population of more 'modern' people in Brazil burn it down. Human collective decisions are invariably mediocre at best, we are at our best (also our worst at times) when one smart individual is in control. The US government was partitioned into large groups to CREATE gridlock. There is an inverse proportion of IQ and the size of the group when it comes to humans, it's obvious that the reverse is true for insect collectives (hence the definition of collective).

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