158 Chapter VIIL 



the community. The beetle Atemeles emarginatus was 

 always amicably received, when one or the other of the 

 following conditions was verified. Either a number of 

 fusca had to be kept as slaves in the colony, or I had to 

 isolate a few of the sanguined in a little glass, to quar- 

 antine them for some days with the new guest, before 

 introducing him to the company of the other ants. In 

 the first case the fusca received the beetle, and intro- 

 duced him to the san guinea; in the latter case he was 

 introduced by the sanguined which had allowed him to 

 approach and touch them during the period of isolation, 

 and had finally licked his aromatic secretions. I found 

 out by experiments that it is not only the odor of the 

 salivary gland-secretions of their companions which in- 

 duces the ants to grant permanent admission into the 

 colony to the beetle which has been licked by one of 

 their number, but that it is a genuine instance of learn- 

 ing by imitation. 1 The same happened in the admis- 

 sion given to an Atemeles emarginatus by a mixed col- 

 ony of Formica pratensis and F. Fusca, in which case 

 the former learned by the example of the latter, how 

 to treat the beetle. 2 



The great importance of the social instinct for com- 

 munities of ants follows from the fact that their sensile 

 power of communication, their so-called feeler lan- 

 guage, would be purposeless without it. 3 For the re- 

 sult of tapping one another's heads consists principally 



) "Die psychischen Faehigkeiten der Ameisen," p. 96 ff. 



2 ) "Die zusammengesetzten Nester und gemischten Kolonien der 

 Ameisen," p. 174. "Die psych. Faehigkeiten . . . ," pp. 99 and 100. 



3 ) See "Vergleichende Studien" (A. Aufl.), p. 10 and "Die psychi- 

 schen Faehigkeiten der Ameisen," pp. 59-73 and 100. 



