84 ANIMAL INTELLIGENCE. 



* some of the most anomalous forms of coleopterous insects 

 are those which live solely in the nests of ants.' Sir 

 John Lubbock also, and other observers whom we need 

 not wait to cite, mention similar facts. The Eev. Mr. 

 White says that altogether 40 distinct species of Coleoptera, 

 most of which he has in his own collection, are known 

 to inhabit the nests of various species of ants, and to 

 occur nowhere else. 



As in all these cases the ants live on amicable terms 

 with their guests, and in some cases even bestow labour 

 upon them (as in carrying them from one nest to another 

 during migration), it is evident that these insects are not 

 only tolerated, but fostered by the ants. Moreover, as it 

 seems absurd to credit ants with any mere fancy or caprice 

 such as that of keeping pets, we can only conclude that 

 these insects, like the aphides, are of some use to their 

 hosts, although we are not yet in a position to surmise 

 what this use can be. 



Habits of Sleep and Cleanliness. — It is probable that 

 all species of ants enjoy periods of true sleep alternating 

 with those of activity; but actual observations on this 

 subject have only been made on two or three species. 

 The following is MacCook's account of these habits in the 

 harvesting ant of Texas : — 



The observation upon the ants now before me began at 

 8 o'clock; at 11 p.m. the cluster had nearly dissolved, only a 

 few being asleep. To illustrate the soundness of this sleep I 

 take the quill pen with which I write, and apply the feather 

 end of it to an ant who is sleeping upon the soil. She has 

 chosen a little oval depression in the surface, and lies with 

 abdomen upon the raised edge, and face toward the lamp. Her 

 legs are drawn up close to the body. She is perfectly still. I 

 gently draw the feather tip along the body, stroking * with the 

 fur,' if I may so say. There is no motion. Again and again 

 this action is repeated, the stroke gradually being made heavier, 

 although always quite gentle. Still there is no change. The 

 strokes are now directed upon the head, with the same result. 

 Now the tip is applied to the neck, the point at which the head 

 is united to the pro-thorax, with a waving motion intended to 

 produce a sensation of tickling. The ant remains motionless. 

 After continuing these experiments for several minutes, I 



