ants make and use tools

Ants make and use tools (my observation) 1^st November 2004

After collecting a mated queen Lasius Niger during summer 2004 I carefully observed the development of the growing colony through a perspex window in their formicarium.

There were excellent times to watch amazing things I had never seen before. One example was when three ants helped a new born (still white) ant out of its cocoon. They held it outstretched by its legs and head between their jaws while a fourth ant took a tiny piece of sand between its own jaws and delicately scrubbed it all over as if giving it a bath. This seemed to stimulate the ant and it seemed a very careful nurturing behaviour by its sisters.

Around 12 weeks after I put the queen inside the nest there were a handful of busy workers intent on tunneling and creating new spaces. They made the queens chamber big enough for her to get around and made lots of small rooms where ants at various stages of development would be placed and moved around to ensure optimum condtions for them.

I fed them a small blow fly which they sucked completely dry by chewing a hole through the eye.

I watched the ants attempt to cut off a leg from the fly which took considerable time and effort. I assumed it was to be carved up for food.

The next day I noticed that the fly’s leg was inside the nest chamber. I thought that perhaps this represented the meat portion of the diet that the final stage larvae with their little mouths required.

As I found out after some research, black ants do not store food in the actual nest, they carry all their food in a shared stomach so that individuals can share it easily and I would imagine there are good reasons for this. Perhaps in the event of cataclysmic events to the nest, the ants can survive more easily. Perhaps also not storing food makes predation of the nest less likely as other creatures would not be attracted to the smell of their larder, furthermore it is a way of ensuring rotting food does not infect or otherwise dirty the nest. Space is also at a premium and not storing food in the nest seems a good evolutionary adaptation.

However the leg was not consumed at all. On closer inspection it appeared that the leg had been modified. The thigh section of the leg had been cut at a specific site so as to create an equal length hinge to the foreleg and thigh section. The foot, complete with hairs was also left creating a second smaller hinge and foot. I observed that this leg had a habit of being left at the furthermost end of the current tunneling operation. I realised that it was not for food and resembled a very carefully crafted tool as if left by a builder for use later. On closer inspection it appeared that the leg was left in a brace position to ensure that the tunnel did not collapse. Over the next week or so I noticed that the leg would invariably be left in position within a tunnel either at the furthermost end of a tunnel or where a large overhang remained, unexcavated.

There were two basic positions for the leg, either as a ladder in steep tunnels or as a brace for overhanging excavation works.

This seems absolutely fascinating to me as the flexibility of the joints seems to make this an extremely adaptable and reliable hardwearing chitin tool, the angles can be adapted as required and as observed in various tunnels.

my guess is that if you took a queen from the same nest location (and I think I know the location of this mother colony) that you would find this behaviour repeated in her daughters colony as culture. i also think that black ants everywhere can and would do this, but if it is indeed localised behaviout then that is another aspect to consider.

I have some photographic evidence of the brace being used for an overhang in an unfinished tunnel although on reflection I should have documented all examples of this tool in various locations around the nest. Much to my dismay the queen died yesterday so the remaining ants
do not have long to display their building skills. They also don’t seem to care for much other than eating now. Interestingly the leg that I do have photos of was actually a piece of plant root, although i have still got the actual leg!

At the entrance to the nest was a large tunnel covered by a mound of excavated sand.

I observed this small piece of plant root performing the same function as the flys leg. It was used to ensure the collapse of the entrance did not occur. At the time I thought it was another flys leg
but was equally amazed at the adaptability of material use.

I inadvertently made the nest very dry as it had become too moist by adding too much water in preparation. There was a lot of condensation so I stopped adding water for a while. The nest was composed of sand and it seems that the behaviour was a response to the fragility of the dry sand nest.

I added a very small amount of soil from a plant pot to the nest material before adding the Queen and when I eventually emptied the nest after they had died, I carefully extracted the small pieces of plant matter from the sand. There were literally a very few small pieces of plant matter which seem to have been used for the same purpose and nothing else but sand.

As mentioned above I incorrectly identified this piece of plant matter as another fly leg and foolishly published a photo on the internet with diagrammatical explanation. Oh well, i was excited and got slightly ahead of myself but that seems ok in retrospect.

I photographed the nest contents after I emptied it and sieved through it with a magnifying glass and tweezers until i had every piece of material separated from the sand. The macro photos that I took clearly show the fly and its severed leg and also the small pieces of plant root which were used in a similar fashion.

I have carefully stored these items in a box for posterity and may publish the photos of the recovered contents at a later date if I have the time.

I tried to repeat the experiement in 2005 but unfortunately the colony did not thrive.

I will repeat it again this year when the queen ants appear in the summer months.

This time I will be more careful and I aim to document with video the actual behaviour that I observed for hours on end.

It seems that at one level there are implications for the discovery as nobody seems to credit ants with toolmaking ability and if ants can make and use tools, how many neurons does it take to become intelligent. I know there is a strange dynamic with colony insects but the individual ants seem to have very good facilities as individuals. Alas I am not a qualified scientist and have little experience of animal psychology so there are limits to how far I can take the findings.

I have long been interested in the idea of animal intelligence and consider our human conceit that we are ‘superior creatures’ not only a misnomer but one of the reasons we usually show little thought for the other creatures on our planet in our quest for consuming our shared resources.

I do know that initially it was thought impossible for other apes than humans to use tools, and it has transpired over time that other creatures including certain bird species can utlisise tools, so time will tell.

I do not currently have the resources or time required to obtain the 30 observations over 3 nests, which would be required by scientists to prove the facts, but I am sure in time it will be shown by others eventually.

I did make a bit of a storm with the ant experts in ant forums who seemed to be either very interested or lambasted my amateurish approach. I believe that the entire forum discussion is still available at myrmecology.org.

With hindsight I would have been more pragmatic in my discussions and hopefully would have got someone interested enough to research the ideas themselves. Who knows, there might be someone out there who thought it was worth investigating further and will turn up the proof.

I have been a keen amateur entomologist since the age of five when I raised my first brood of Coleoptera (ladybirds) and continue to have an enduring fascination with all (especially colony insects.)