LIFE HISTORY OF CARPENTER ANT. 20O, 



linid beetles, several species of Blattidae, and the adults of the 

 wood-boring larvae. Other ants are also often very close neigh- 

 bors of the species I have studied. I have found two colonies of 

 small ants in chambers which were connected on all sides with 

 those occupied by the larger ants. One of these was a colony 

 of Myrmecina americana, which I found with a colony of C. fer- 

 ruginens, and the other a colony of Monomorum pharaonis, which 

 I found with a colony of C. pennsylv aniens. The insectory is 

 badly infested with this latter species and they have helped them- 

 selves liberally to the food that I have given my ants, and have 

 especially thrived on the dead ants which my colonies threw upon 

 their rubbish heaps. These little ants are not noticed by the 

 larger ones, and doubtless in the natural nests they subsist largely 

 by picking up the "crumbs" about the formicaries of the larger 



species. 



Instincts and Intelligence. 



The many remarkable feats performed by ants in the round of 

 their daily life have led observers to form various conclusions as 

 to the parts played by instincts and intelligence respectively, in 

 controlling their movements. Lubbock, on the one hand, con- 

 cludes that ants rank next to man in the degree of intelligence 

 possessed ("Ants, Bees and Wasps," p. i), and on the other 

 hand, Wassmann endeavors to show that they are absolutely 

 void of pure intelligence (" Psychology of Ants "). 



On this subject I have made the following observations and 

 experiments : 



Observation i. — On the evening of August i, 1906, I planned 

 to count the number of workers of outdoor colony A, which 

 passed a certain point between the nest and the aphid tree, in a 

 given time. In order to do so I cleared away the weeds so that 

 I might see them more easily. I soon noticed, however, that 

 ants were collecting on both sides of the place where I had dis- 

 turbed the path, and they refused to cross the disturbed area. 

 Considerable excitement seemed to prevail on both sides, and 

 the number kept increasing, especially on the side toward the 

 nest. Some of these returned to the nest and some of the others 

 returned to the aphid tree. Finally, after about thirty minutes, 

 when approximately one hundred ants were assembled on the 



