From time immemorial, people have been dreaming about understanding animal “languages”. The problem of cracking animals’ codes have become especially attractive since the great “linguistic” potential was discovered in several highly social and intelligent species by means of intermediary artificial languages. Being applied to apes, dolphins and grеy parrots, this method has revealed astonishing mental skills in the subjects. However, surprisingly little is known yet about natural communication systems of animals.

With Boris Ryabko we have suggested to apply ideas of Information Theory for studying natural communications of animals, that is, not to decipher signals, but to investigate the very process of information transmission by measuring time duration which the animals spend on transmitting messages of different lengths and complexity. The use of ideas of Information Theory enabled us to demonstrate that highly social ant species (mainly red wood ants) possess symbolic and flexible communication system which allows them to transfer information concerning coordinates and number of objects. These intelligent insects even can grasp regularities and use them for shortening messages. The detailed description of the obtained results can be found in: Reznikova&Ryabko, 2012,  Reznikova&Ryabko, 2011,    Reznikova, 2008 , Ryabko & Reznikova, 1996 ,  Reznikova & Ryabko, 1994 and other publications

How to ask ants to transmit some bits of information to each other?

The experimental paradigm of our approach is simple. All we need to do is to establish a situation where ants must transfer a specific amount of information to each other. The crucial idea is that we know exactly the quantity of information to be transferred and the time needed to do it. To organize the process of information transmission between ants, a special maze has been used, called a “binary tree” , where the number and sequence of turns towards the goal correspond to the amount of information to be transferred.

In our experiments ants are housed in the laboratory arena which is divided into two parts that are connected with a removable bridge, one contains a nest and another contains a set up. Here is the binary tree maze placed in a base with water.

The Binary tree set up allows us to measure the rate of information transmission in ants (this can be measured in bits per minute), and subsequently to reveal ants' ability to grasp regularities and to compress information. The problem of searching a trough with syrup on the binary tree in lab experiments is based on a natural situation of aphid-milking, when ants have to search for a certain branch with an aphid colony within a tree crown.

Natural situation of aphid-milking

(video by Natalia Atsarkina) 

 

We place a scouting ant on the trough with syrup and it repeats it's trip for several time before remembering a path and mobilizing it's constant group of foragers

A scout's trip ("exam")

(video by Natalia Atsarkina)

During "examinations" the trough contains water instead of syrup. We measure the duration of contacts between every scout with its foraging "team" in seconds.

A process of the contact between the scout ant its team

 (video by Natalia Atsarkina)

After the contact we remove the scout and isolate it for a while. In order to avoid using odour trails by ants we replace a maze for a fresh one and syrup for water in the trough. One can see here several removable mazes near the arena.

The group of foragers ("team") has now to search for the goal by themselves, without their guide, basing on the information gained from the scout. They have to use a fresh maze with an empty trough. Ants will be immediately rewarded after they reach a goal.

A team on the binary tree ("exam")

 (video by Natalia Atsarkina)

How to use ants communication for asking them about their numerical skills

Numerical competence is one of the main intriguing domains of animal intelligence. Recent studies have demonstrated some species from mealy beetles to elephants as being able to judge about numbers of stimuli, including things, and sounds, and maybe smells. However, we are still lacking an adequate “language” for comparative analysis. 

We suggested a new experimental paradigm which is based on ideas of information theory and is the first one to exploit natural communicative systems of animals. In our experiments ant scouts were required to transfer to foragers in a laboratory nest the information about which branch of a special “counting maze” they had to go to in order to obtain syrup. “Counting maze” is a collective name for several variants of set-ups.

The experiments were based on a procedure similar to the binary tree study. The main idea of this experimental paradigm is that experimenters can judge how ants represent numbers by estimating how much time individual ants spend on “pronouncing” numbers, that is, on transferring information about index numbers of branch.

The comb-like set-ups for studying numerical competence in ants

 A team on a comb-like maze ("exam")

The detailed description of the obtained results can be found in Reznikova&Ryabko, 2012,  Reznikova&Ryabko, 2011,  and other publications

See also the "Ants and Bits" plenary lecture presented at the 2011 IEEE International Symposium of Information Theory.

Ant language in popular press

In Soviet times, our research could not get much (if any) international exposure, but the situation changed in 1991. The first essay in popular press concerns my very first trip abroad  in August 1991. Following my report on ant language at the 22^nd Ethological Conference in Kyoto, Miles Barton published a brief article "Learning to speak ant" in  BBC Wildlife.

The second essay was published in The Independent, Nov. 1997 by a famous British researcher on artificial intelligence Donald Michie (1923-2007) who braved a journey to Novosibirsk in order to see our experiments on site. He invited us to take part in the WS on Artificial Intelligence in York, 2000, and to publish a paper in ETAI.

Here are some more recent essays on ant math in popular press:

Ants may be math wizards of the Animal Kingdom

Ants are smarter than human 5-th grades in math

Ants show an aptitude for arithmetic