My PhD supervisor, ‘Prof’, and his wife ‘Wink’ used to spend their summers camping by the sea in northern Greece. Prof spent his days profitably studying an aspect of the area’s local fauna.

Prof, a good scientist, had an insatiable curiosity about everything. This knew no rest periods. Quite a few years before I met him, Prof and his family began taking summer holidays in Greece. They camped there in their caravan, which they hauled across Europe with their old Land Rover. At first, they visited many of the tourist sites in Greece as well as spending time relaxing by the sea. One of the beach resorts that they visited was Platamon in the Greek part of Macedonia. While his family were enjoying the sun and swimming, Prof noticed some large ants scurrying about on the sand. They were large enough to be seen from quite a distance. What interested him particularly was that they were most active around midday when the air temperature was at its greatest. At this time of day, hardly any creatures, let alone insects, were active. The temperature of the surface of the sandy soil on which these ants were busy carrying out their daily chores was in excess of 40 degrees Celsius. The two-coloured (red and black) ants whose bellies were carried vertically were members of the species known to taxonomists as Cataglyphis bicolor. Prof nicknamed these ants ‘catas’.

A Cataglyphis ant. [Source: https://www.inaturalist.org/taxa/82193-Cataglyphis%5D

These desert ants caught Prof’s interest. After all, they were far more interesting to him than swimming or reading books. Why bother with fiction, he would have asked, when life itself is so interesting? This fascination with insects was not new; it began in his childhood days, when he had been keen on entomology. He began observing the ants in his usual methodical way. This had two results. First, their behaviour began to obsess him to such an extent that his interest in connective tissue gave way to his study of the ants’ behaviour and ecology. Secondly, because of this interest every summer holiday had to be spent in Platamon. He could not get enough of his ants. I will return to them later.

Prof’s curiosity was unending.  It extended to bizarre extremes as I was to discover shortly after I began working with him. Wink was keen on arranging large parties at their home in the Home Counties. Prof noted that the guests standing chatting with glasses of drinks in one hand helped themselves to whatever was offered to them on trays. At one of these parties, Prof, who was not keen on small talk, retired to the kitchen and opened a tin of fish-flavoured cat food. He spread this in thin layers on salty Ritz Crackers before laying them out neatly on a tray. He called the pretty young daughter of one of his guests, one of Wink’s cousins, into the kitchen and asked her to offer his unusual snacks to the guests. He wanted to test his theory that people at parties would eat anything that was offered on a tray. The young girl, who was aware what Prof was up to, began carrying the fishy snacks towards the living room, but halfway down the long corridor she turned around and returned to the kitchen. She told Prof that she felt a fit of giggles was about to begin, and that she would not be able to keep a straight face whilst offering the crackers to the guests. Wink, who told me about this later, was both furious and amused.

After many years without one, Prof and Wink acquired a small camping refrigerator. This allowed my friends to refrigerate bacon and butter and to keep milk for longer periods in the summer heat. It also allowed Prof to refine his research in an interesting way. He used to pick up a cata and then pop it into a small specimen jar. Ant and jar were then put in the refrigerator for a few minutes. The ant’s metabolism slowed down in the cold, and the creature became immobile. When it was so anaesthetised, Prof removed the ant and painted a small identification mark on its belly with the kind of paint (it was the ‘Humbro’ brand) that was used to decorate model aeroplanes made from kits such as used to be manufactured by companies like Airfix. When the ant warmed up and awoke, Prof placed it carefully exactly where he had found it.

Prof ‘stalking’ marked ants in northern Greece

Prof was delighted when he saw his first marked ant reappearing the following day, and again the day after. Now, he was able to follow the activities of individual ants. The marked ants were not given numbers; they were given names. Thus, ‘Alybel’ had a spot of silver coloured aluminium painted on its belly; ‘H’, who had a particularly plump belly, was named after Prof’s school friend, the larger than average Canon H; and so on. Another was named ‘Canon’. These names appeared in the scientific papers that Prof published eventually.

Once he had developed a method for tagging ants, Prof began to follow them about as they carried out their daily labours. He bought an enormous number of aluminium garden tags before leaving England for Platamon. Each of these had a rectangular part that was to be used for writing the name of a plant and a contiguous tapering section that was supposed to be stuck into the soil next to the labelled plant or seedling. Prof numbered his miniature labelling stakes from 1 upwards and kept them in numerical order on a long wire. When a marked ant poked its head out of the nest, Prof began stalking it. Every 10 seconds, he placed one of his numbers with its sharp point on the position where the ant had been, beginning with tag number 1, and then 10 seconds later number 2, and so on until the ant returned to its nest. Thus, he left a trail of aluminium labels that mapped out the ant’s footsteps. After the ant returned to the nest, he plotted out the ant’s exact path on a paper map. He did this without difficulty as he had learned how to draw maps during his spell in the army at the end of WW2.

While Prof was stalking ants, he must have looked quite odd to the casual passers-by. Dressed in a khaki safari jacket and unfashionably long khaki shorts, his head, which was largely hidden by a wide-brimmed straw hat, bobbed up and down at regular intervals as he laid each successive marker. He hoped that no one would disturb him or his markers but made no fuss when the goatherd’s goats strolled over his open-air laboratory. Once, I remember him trying to explain to the goatherd (in broken Modern Greek) what he was trying to do. The goat man remained mystified. The Greeks, incidentally, referred to the catas as κλέφτες (‘thieves’ or ‘robbers’). Prof used to wonder whether the catas, which were capable of carrying loads much heavier than themselves, were the same ants that Herodotus claims carried gold in India.

Herodotus (c480-c429 BC) wrote

(see: http://www.livius.org/sources/content/herodotus/the-gold-digging-ants/):

“Besides these, there are Indians of another tribe, who border on the city of Caspatyrus, and the country of Pactyica; these people dwell northward of all the rest of the Indians, and follow nearly the same mode of life as the Bactrians. They are more warlike than any of the other tribes, and from them the men are sent forth who go to procure the gold. For it is in this part of India that the sandy desert lies. Here, in this desert, there live amid the sand great ants, in size somewhat less than dogs, but bigger than foxes. The Persian king has a number of them, which have been caught by the hunters in the land whereof we are speaking. Those ants make their dwellings under ground, and like the Greek ants, which they very much resemble in shape, throw up sand heaps as they burrow. Now the sand which they throw up is full of gold. The Indians, when they go into the desert to collect this sand, take three camels and harness them together, a female in the middle and a male on either side, in a leading rein. The rider sits on the female, and they are particular to choose for the purpose one that has but just dropped her young; for their female camels can run as fast as horses, while they bear burthens very much better.”

However, these ants, according to Herodotus, hid from the heat:

“When the Indians therefore have thus equipped themselves they set off in quest of the gold, calculating the time so that they may be engaged in seizing it during the most sultry part of the day, when the ants hide themselves to escape the heat.”

So, the ants that Herodotus describe differed from the Cataglyphis ants in northern Greece in that they became invisible during the hottest part of the day. Maybe, it was hotter in the area that the ancient Greek described than in Greece.