60 I March, 



ON THE OEIGIN OF ANTS' NESTS. 

 BY W. W. SMITH. 



Before 1S81, the year in which Sir John Lubbock published his 

 volume on "Ants, Bees, and Wasps," nothing absolutely was known 

 of the mode, or means of origin of ants' nests. Various theories had 

 been suggested and others put forward to explain the origin of young 

 communities. But the experiments conducted to discover their origin 

 before Lubbock's time were inconclusive ; thus the interesting fact 

 was left to be discovered by that patient and accurate experimenter 

 and observer of the habits of the social Hymenoptera. To every 

 student of any group of insects there are generally some special 

 characteristics in their history which he seeks to discover, and certainly 

 the habits of ants offers an almost inexhaustible field for this purpose. 

 Three principal modes of origin of ants' nests had been suggested 

 before the problem was solved by Lubbock. In the words of the 

 latter they are as follows: — "After the morning's flight the young 

 queen may either 



(1) Join her own or some other old nest ; 



(2) Associate herself with a certain number of workers, and with 



their assistance commence a new nest ; or 



(3) Found a new nest by herself." 



In the case of Myrmica ruginodis, Lubbock showed conclusively 

 that under certain conditions the queens of the species are endowed 

 wdth the power to found communities, as by isolating two pairs in the 

 autumn they succeeded in establishing a small nest in the following 

 summer (Ants, Bees, and Wasps, pp. 32, 33). The patient care 

 bestowed on them, and the very favourable conditions surrounding 

 their isolation, viz., " damp earth, food, and water," were doubtless 

 all that was necessary to enable them to found a nest. 



Having devoted much time for many years to observing the habits 

 of several species of New Zealand ants in their natural state, I am 

 convinced that none of the three modes suggested would explain the 

 origin of the nests of any indigenous species I have observed. My 

 observations have been made chiefly on two species of Tetramorium 

 (T. nitidum, T. striatum, Smith), both being common on the banks and 

 old beds of the Ashburton river, and within a few minutes walk from 

 home. The nests occur under various sized stones lying partly buried 

 in the sandy soil ; they also occur on the terraces of the river, and on 

 the open plains, but more so on the stony parts. The roots of the 

 low-growing stunted vegetation form a fine network beneath the 



