COMMUNICATION AMONG INSECTS McINDOO 553 



hearing aids in communication, but as we have no definite knowledge 

 that ants hear, at least as we humans hear, we can not consider hear- 

 ing the chief factor; ants, however, can make sounds by stridulating; 

 in other words, by rubbing certain parts of their body against other 

 parts. When ants are in actual contact with one another their acute 

 sense of touch is certainly an important factor in communication, but 

 ants can easily distinguish each other before they come in contact; 

 it is highly probable, therefore, that touch is second in importance 

 to smell. Ants, furthermore, have the habit of making various kinds 

 of signs and gestures, which most writers believe aid them in convey- 

 ing information. Many of their gestures, such as particular move- 

 ments of the antennae, jaws, head, and abdomen, have been inter- 

 preted as signs which may be understood and acted on by other ants. 

 Wasmann has compiled a kind of dictionary, based on a number of 

 different antennal strokes, each supposedly having its own meaning. 

 The meaning depends chiefly on the nature of the stroke, whether 

 quick or slow, heavy or light, at longer or shorter intervals, on the 

 top or side of the head, or only on the antennae, and in still other 

 ways. 



Huber was a firm believer in an antennal language, which is to be 

 classified mostly, if not entirely, as a touch language. He tells about 

 some ants which he had held as captives four months, during which 

 they had not communicated with their former companions in the nest. 

 One day some of these captives accident!}^ escaped ; they were found 

 and recognized by their former mates, who caressed them with their 

 antennae, took them up by tlie jaws, and led them back to the nest. 

 The ants in the nest presently went in a crowd to seek the remaining 

 captives, and after some time had returned all of them to their old 

 home. 



In the case of both ants and bees the utmost harmony reigns be- 

 tween those belonging to the same community, whereas all others are 

 enemies. It is particularly true, remarks Lubbock, that ants " know " 

 all their comrades, even after a long separation. If a strange ant 

 is put among ants of another nest she is at once attacked. Tliis 

 implies that all ants or all bees of a community have the power of 

 recognizing one another; a most surprising fact when we consider 

 the shortness of their lives and the immense numbers in a single 

 community. Lubbock returned some ants to their old nest after 

 a separation of a year and nine months, yet they were amicably 

 received and evidently recognized as friends. He finally concluded 

 that ants recognize their friends even when intoxicated, and knpw 

 the young born in their own nest, even when the young have been 

 taken out of the cocoons by strangers. These facts indicate strongly 

 that recognition is not effected by means of signs and passwords, but 

 by odors. 



