24 Chapter I. 



guests. In the front nest we see generally a number of 

 ants basking in the sun or engaging in different labors. 

 In the top nest a small number of sanguinea, rufa and 

 pratensis are usually found either on guard, or wait- 

 ing for the flies or other food which I occasionally 

 throw in. In the glass bulb of the feeding tube, even 

 if it happens to contain no sugar or honey, there are 

 always one or two ants, mostly fusca or ruft- 

 barbis, which have a special liking for this depart- 

 ment. Even on the dumping grounds, whither the 

 ants carry their dead, there are, as a rule, a few ants 

 to be found, remaining immovable and watching for 

 any suspicious circumstance in the nest or in its 

 vicinity. On March 26, 1896, from morning till eve- 

 ning one F. fiisca and one F. pratensis were posted in 

 the refuse nest ; on March 27, at 7 a. m. two F. pra- 

 tensis; at 10 a. m. two F. sanguinea took their place. 

 On March 28, in the forenoon, one sanguinea 

 was on guard, which having been taken out by 

 me and confined was soon after replaced by another 

 sanguinea for the rest of the day. On March 29 the 

 whole day one sanguinea ; on March, 30 at 7 :3O a. m., 

 two fusca ; when at 8 a. m. I had taken out and con- 

 fined one of the two, I found that within the space of 

 half an hour another fusca had taken its place, where- 

 upon both remained there during the whole of the 

 forenoon, etc. Only during winter, after I had com- 

 pletely emptied the refuse nest and left it in the 

 same condition for a long time, no ants were seen 

 there for several weeks, because this part of their 

 nest was no longer 6f any vital interest to them, and 

 because the cool temperature kept them in the main 



