HYMENOPTERA 961 



It is usually yellowish brown, with a black abdomen; but it varies 

 greatly in color. Its favorite nesting-place is under stones or under- 

 neath and within the decayed matter of old logs and stimips. Out 

 of this material the ants sometimes make a paper-lilce pulp with 

 which they build a nest attached to the side of a log, or even to the 

 branches of a shrub at some distance from the ground. While such 

 nests are uncommon these ants often build small sheds at some dis- 

 tance from the nest, over the herds of aphids or coccids from which 

 they obtain honey-dew (Fig. 1179). In these cases the aphids or 



Fig. 1 179. — A "cow-shed" built by ants. (From A. B. Comstock, Handbook of 

 Nature Study.) 



coccids are huddled together on a branch, from which they are de- 

 riving their nourishment, and are completely covered by the "cow- 

 shed" built by the ants. 



An inquiline or guest ant, Leptothorax enter soni. — This ant, the 

 habits of which are described in detail by Wheeler, lives only associ- 

 ated with another species, Myrmtcdbrevinodis, The Myrmica "builds 

 its nest in the soil of bogs, in clumps of moss {Polytrichimi) or under 

 logs and stones, and the Leptothorax excavates small cavities near 

 the surface and communicating by means of short, tenuous galleries 

 with those of its host. The broods of both species are brought up 

 separately. The Leptothorax, though consorting freely with the 

 Myrmica workers in their galleries, resents any intrusion of these ants 

 into its own chambers. The inquilines do not leave the nest to forage 

 but obtain all their food in a very interesting manner, from their 

 hosts. Both in the natural and artificial nests the Leptothorax are 

 seen to mount the backs of the Myrmicas and to lick or shampoo 



