102 Chapter III. 



nests, have a predilection for building under stones. 

 This saves them a great deal of work and gives the 

 whole building greater firmness, and, moreover, in 

 such a nest the heat of the sun more easily penetrates 

 to the interior. In heaths also, where stones are rather 

 rare, instances of such stolen nests may occur. A nest 

 of F. san guinea* on which in 1894 I had placed a clod 

 of heath serving it henceforth as roof, had in 1895 

 passed into the possession of a colony of Lasius niger; 

 in the years 1896-98, it was again inhabited by F. son- 

 guinea. A short time ago, in the same region near 

 Exaten, I found a rather extensive earth hill supported 

 in the centre by a bunch of heather and inhabited by 

 a large colony of F. rufibarbis. The ants had collected 

 on the surface a small heap of dry heather-leaves, as 

 they generally do there. The earth hill itself, how- 

 ever, judging by its architecture, was an old nest of 

 L. niger, which subsequently had been occupied by 

 the rufibarbis. History is silent as to whether the orig- 

 inal builders of the nest had quitted it before the time 

 of the foreign invasion, or whether they were com- 

 pelled by force to evacuate it. 



F. san guinea are a restless people. They frequently 

 desert their nests, which are then taken possession of 

 by other, smaller species (especially Tetramorium 

 caespitum, L. niger and alienus). I have noted a num- 

 ber of such instances in my records of the last few 

 years ; it may suffice to mention one of the most 

 remarkable. A large colony of F. sanguined (No. 72 

 of my stat. map), in 1895 and 1896, had inhabited a 

 group of three nests, distant from one another 3 and 



Colony No. 155 of the statistical map. 



