It is difficult to imagine why these Indian ants should turn out from their nests the very seeds which it had cost them so much labour to collect, and the more so as we find that these seeds are devoured by birds. It seems just possible, however, that the ants, remaining torpid during the rainy season, do not require the seeds, and know that, under these circumstances, if left in the nest, they would sprout, and choke up the galleries and granaries. Perhaps also they may have learned that a certain number of the ejected seeds will spring up and afford future harvests within easy reach of the nest.
All this, however, and especially the suggestion as to the dormant condition of the ants during the rainy season, might easily be proved or disproved by direct observation; and at present we have nothing but mere speculation to go upon.
It is curious to find that the native population in a certain part of India pay a kind of tribute to the ants, for Dr. King informs me that the Hindoos in Rajputana, a province in which the old traditions and superstitions retain especial hold, have a custom of scattering dry rice and sugar for the ants, and thus apparently recognise both their love of sweet things and their habit of collecting seeds. It may be that this custom is now little more than a meaningless rite; but in the past it probably had its origin, either in a wish to propitiate the good will and avert the destructive attacks of creatures which are the scourge and dread of entire districts, or in a sentiment of combined fear and admiration—fear of the power, and admiration of the energy, forethought, perseverance, and sense of duty to the community displayed by these marvellous insects.
That the latter feeling may have had some share in prompting this act is suggested by another custom which is stated[117] to prevail in Arabia, in accordance with which an ant is placed in the hand of a newly-born child, in order that its virtues may pass into and possess the infant.
[117] Freytag, paragraph under the Arabic word for Ant, in his Lexicon Arabico-Latinum, vol. iv. p. 339, where he quotes from a local dictionary.
Among the many curious and obscure features in the economy of ants, one of the most interesting is the occasional presence in their nests of different creatures which live among and often in harmony with them, the nature of the relations between host and guest being for the most part quite unknown.
When examining the contents of some granaries from an extensive nest of Atta structor at Mentone last spring (1874), I found large numbers of a minute, shining-brown beetle moving about among the seeds. These little creatures were themselves not unlike some very small seeds, and were of an elliptic form, measuring a trifle less than one line in length. They proved to belong to the scarce and very restricted genus Coluocera.[118] This species, named by Kraatz C. attæ, on account of its inhabiting the nests of ants belonging to the genus Atta, has been found in Greece.
[118] I am indebted to Mr. F. Smith of the British Museum for the name of this beetle and for the following reference to its description; Kraatz in Berliner Entomologische Zeitschrift for 1858-9, p. 140.
Mr. Bates,[119] in his most interesting account of his travels on the Amazons, remarks upon the singular fact, of which the above instance is an example: "that some of the most anomalous forms of Coleopterous insects are those which live solely in the nests of ants," and he then goes on to allude to the strange snake Amphisbæna, a native of that region, which also lives in the nests of the Sauba ants (Œcodoma cephalotes), observing how curious it is that an abnormal form of snakes should be found in the society of these insects. He is of opinion, however, that the Amphisbæna is not an inoffensive guest, but lives upon the ants whose nest it selects for its home.
[119] Naturalist on the Amazons, p. 61-2 (Ed. 2, 1864).