INTELLIGENCE OF ANTS. 509 



haps safest to suppose that these insects, like the aphides, are of some 

 use to their masters, although we are not yet in a position to surmise 

 what this use can be. 



Sleep and Cleanliness. It is probable that all ants enjoy periods 

 of true slumber alternating with those of activity ; but actual obser- 

 vations on this subject have only been made in the case of two or 

 three species. McCook says that the harvesting ants of Texas sleep 

 so soundly that they may be pretty severely stroked with a feather 

 without being aroused ; but they are immediately awakened by a sharp 

 tap. On awakening they often stretch their limbs in a manner pre- 

 cisely resembling that of warm-blooded animals, and even yawn the 

 latter action being " very like that of the human animal ; the mandi- 

 bles are thrown open with the peculiar muscular strain .which is fa- 

 miliar to all readers ; the tongue is also sometimes thrust out." The 

 ordinary duration of sleep in this species is about three hours. 



Invariably on awakening, and often at other times, the ants per- 

 form, like many other insects, elaborate processes of washing and 

 brushing. But, unlike other insects, ants assist one another in the 

 performance of their toilet. The author just quoted describes the 

 whole process in the genus Atta. The cleanser begins with washing 

 the face of her companion, and then passes on to the thorax, legs, and 

 abdomen. 



The attitude of the cleansed all this while is one of intense satisfaction, quite 

 resembling that of a family dog when one is scratching the back of his neck. 

 The insect stretches out her limbs, and, as her friend takes them successively 

 into hand, yields them limp and supple to her manipulation ; she rolls gently 

 over on her side, even quite over on her back, and with all her limbs relaxed 

 presents a perfect picture of muscular surrender and ease. The pleasure which 

 the creatures take in being thus " combed " and " sponged " is really enjoyable 

 to the observer. I have seen an ant kneel down before another and thrust for- 

 ward the head drooping quite under the face, and lie there motionless, thus ex- 

 pressing, as plainly as sign-language could, her desire to be cleansed. I at once 

 understood the gesture, and so did the supplicated ant, for she at once went to 

 work. 



Bates also has described similar facts with regard to ants of another 

 genus the Ecitons, 



Play and Leisure. The life of ants is not all work, or, at least, 

 is not so in all species. Huber describes regular gymnastic sports as 

 practiced by the species pratensis. They raise themselves on their 

 hind-legs to wrestle and throw pretended antagonists with their fore- 

 legs, run after each other^ and seem to play at hide and seek. When 

 one is victorious in a display of strength, it often seizes all the others 

 in the ring, and tumbles them about like nine-pins. Forel has amply 

 confirmed these observations of Huber, and says that the chasing, 

 struggling, and rolling together upon the ground, pulling each other 

 in and out of the entrances, etc., irresistibly reminded him of romping 



