ANTS — SLEEP AND CLEANLINESS. 85 



arouse the sleeper by a sharp touch of the quill. She stretches 

 out her head, then her legs, which she also shakes, steps nearer 

 to the light, and begins to cleanse herself in the manner already 

 described. This act invariably follows the waking of ants from 

 sleep. The above description applies to the general habit of 

 somnolence as observed upon the two named species of harvest- 

 ing ants for nearly four months. I have often applied the 

 quill, and even the point of a lead pencil, to the sleeping Flo- 

 ridians without breaking their slumber. There are some other 

 details which have not appeared in the behaviour of the indi- 

 vidual just put under observation. 



Thus, I have several times seen the ants (Crudelis) yawning 

 after awaking. I use this word for lack of one which more 

 accurately expresses the behaviour. The action is very like 

 that of the human animal ; the mandibles are thrown open 

 with the peculiar muscular strain which is familiar to all 

 readers ; the tongue also is sometimes thrust out, and the limbs 

 stretched with the appearance, at least, of that tension which 

 accompanies the yawn in the genus homo. During sleep the 

 antennae have a gentle, quivering, apparently involuntary mo- 

 tion, which seemed to me, at times, to have the regularity of 

 breathing. I also often noted an occasional regular lifting up 

 and setting down of the fore-feet, one leg after another, with 

 almost a rhythmic motion. 



The length of time during which sleep is prolonged appears 

 to vary according to circumstances and, perhaps, organism. 

 The large head-soldiers of the Floridian harvesters appear to 

 have a more sluggish nature than the smaller workers. Their 

 sleep is longer and heavier. The former fact the watch readily 

 determined. The latter appeared from the greater stolidity of 

 the creatures under disturbance. While the ants of one group 

 are taking sleep others may be busy at work, and these stalk 

 among and over the sleepers, jostling them quite vigorously at 

 times. Again, new members occasionally join the group, and, 

 in their desire to get close up to the heat and light, crowd their 

 drowsy comrades aside. I have seen ants who had been at 

 work in the galleries drop their pellets, push thus into the 

 cluster, and presently be apparently sound asleep. This rough 

 treatment is invariably received with perfect good humour, as 

 are like jostlings when the ants are awake. I have never seen 

 the slightest display of anger or attempt to resent disturbance 

 even under these circumstances, so peculiarly calculated to ex- 

 cite the utmost irritation in men. But of course some of the 

 sleepers are aroused. They change position a little, or give 



