ANTS AND THEIR RESEMBLANCE TO AlAN 



749 



BORN WITH A WELIv-STOCKE;d LARDER 



To the former class belongs the queen 

 of the fungus-growing ants, which not 

 only leaves the maternal nest with the 

 mental and bodily endowment of the or- 

 dinary queen, but also inherits some 

 property in the form of a bundle of fun- 

 gus filaments from the gardens of the 

 maternal nest, tucked away in the little 

 pocket in the floor of her mouth. After 

 she has excavated her chamber in the soil 

 and closed its entrance, she is thus in a 

 position not only to bring up a first brood 

 without extraneous aid, but to start the 

 gardens with the fungus pellet, which 

 she spits out, and keeps growing by care- 

 ful weeding and by manuring it from 

 time to time with her excrement, or even 

 with her own broken eggs, till the first- 

 ling workers hatch and begin to bring in 

 the leaf material or caterpillar excre- 

 ment, which is henceforth used as the 

 only substratum for the gardens. 



Very different is the endowment of the 

 queens of a number of parasitic ants. 

 These queens are either very small and 

 feeble or lack the instincts and initiative 

 that would enable them to found a colony 

 independently. They are therefore com- 

 pelled to seek assistance in this arduous 

 task, and they succeed in securing it in 

 one of the three following ways : 



The young queens of some parasitic 

 ants enter the colonies of an allied spe- 

 cies, the workers of which then either 

 kill their own queen and adopt the para- 

 site in her stead or permit the latter to 

 kill their queen. After the reproductive 

 center of the host colony has been thus 

 destroyed, the intrusive queen lays her 

 eggs and permits her young to be 

 brought up by the alien workers. These 

 die off in the course of a few years, but 

 by that time they have reared at least one 

 brood of the parasitic species and the 

 colony, now consisting exclusively of the 

 queen and workers of this species, is 

 sufficiently vigorous to lead an independ- 

 ent existence. This method of colony 

 formation, in which the queen is relieved 

 from the difficult task of feeding and 

 rearing a first brood, has been called tem- 

 porary social parasitism. It is character- 

 istic of many of the largest and most 



prosperous ants of the north temperate 

 zone — e. g., of the mound-building ant 

 of the Alleghanies ( Porrnica exsectoides) 

 and the fallow ant of Europe (P. riifa)^ 



THE KIDNAPPERS 



A different method is adopted by the 

 slave-making ant Formica sanguinea and 

 many of its subspecies (see picture, page 

 755). The young queen enters a nest of 

 the common black Formica fusca or of 

 some one of its many varieties, kills or 

 drives away any of the workers when, 

 irritated by her odor, they rush forth to 

 attack her, then hastily collects a lot of 

 the worker pupse of the fusca and stands 

 guard over and defends them till they 

 hatch. These workers at once affiliate 

 themselves with the queen as intimately 

 as if she were their own mother and 

 bring up her brood for her as soon as it 

 appears. 



The sanguinea young inherit their 

 mother's peculiar instinct to attack the 

 fusca colonies in the neighborhood and 

 to kidnap the worker pupse. They brin^ 

 these pupse back to the maternal nest and 

 eat some of them, but permit others to- 

 hatch and become "auxiliaries," or 

 "slaves." Thus what has been called 

 slavery among ants is merely a form of 

 parasitism, in which the "slave" species 

 is really the host. In old colonies the 

 sanguinea workers often lose the slave- 

 making habit, and as the fusca workers 

 then completely die out, there ensues an 

 emancipation of the sanguinea colony 

 from the host like that observed in the 

 temporary social parasites. 



THE SLAVERS 



A third method is adopted by the young- 

 queens of the permanent social parasites.. 

 These queens enter the colonies of an 

 alien species and are adopted like the 

 queens of the temporary social parasites, 

 after the enforced death of the host 

 queen, but the worker offspring of the 

 parasite are destined always to live with 

 the host species. There are really two- 

 methods of insuring this result. One is 

 by slavery, as in the case of the amazon 

 ants (Folyergus), the workers of which 

 are unable to feed themselves, to care for 



