PERFECT SOCIETIES OF INSECTS. 343 



seen on these nests during the day. It so happened that our visit was 

 paid while the moon was near the full ; so that whether this species is 

 equally vigilant and active in the absence of that luminary yet remains un- 

 certain. Perhaps this circumstance might reconcile Huber's observation 

 with ours, and confirm the accuracy of Aristotle's statement before quoted. 

 To the red-ant, indeed, it is perfectly indifferent whether the moon shine 

 or not ; they are always busy, though not in such numbers as during the 

 day. It is probable that these creatures take their repose at all hours 

 indifferently j for it cannot be supposed that they are employed day and 

 night without rest. 



I have related to you in this and former letters most of the works and 

 employments of ants, but as yet I have given you no account of their 

 roads and trackways. Don't be alarmed, and imagine I am going to 

 repeat to you the fable of the ancients, that they wear a path in the 

 stones 1 ; for I suppose you will scarcely be brought to believe that, as 

 Hannibal cut a way for the passage of his army over the Alps by means 

 of vinegar, so the ants may with equal effect employ the formic acid : but 

 more species than one do really form roads which lead from their for- 

 micaries into the adjoining country. Gould, speaking of his jet-ant (F. 

 fuliginosa], says that they make several main track-ways (streets he calls 

 them), with smaller paths striking off from them, extending sometimes to 

 the distance of forty feet from their nest, and leading to those spots in 

 which they collect their provisions ; that upon these roads they always 

 travel, and are very careful to remove from them bits of sticks, straw, or 

 any thing that may impede their progress ; nay, that they even keep low 

 the herbs and grass which grow in them, by constantly biting them off 2 , 

 so that they may be said to mow their walks. But the best constructors 

 of roads are the hill-ants (F. rufa). Of these De Geer says, " When you 

 keep yourself still, without making any noise, in the woods peopled with 

 these ants, you may hear them very distinctly walking over the dry leaves 

 which are dispersed upon the soil, the claws of their feet producing a 

 slight sound when they lay hold of them. They make in the ground 

 broad paths, well beaten, which may be readily distinguished, and which 

 are formed by the going and coming of innumerable ants, whose custom 

 it is always to travel in the same route." 3 From Huber we further learn 

 that these roads of the hill-ants are sometimes a hundred feet in length, 

 and several inches wide ; and that they are not formed merely by the 

 tread of these creatures, but hollowed out by their labour. 4 Virgil alludes 

 to their tracks in the following animated lines, which, though not alto- 

 gether correct, are very beautiful : 



" So when the pismires, an industrious train, 

 Embodied rob some golden heap of grain, 

 Studious ere stormy winter frowns to lay 

 Safe in their darksome cells the treasured prey ; 

 In one long track the dusky legions lead 

 Their prize in triumph through the verdant mead; 

 Here, bending with the load, a panting throng 

 With force conjoin'd heave some huge grain along. 



i Plin. Nat. Hist. Ixi. c. 29. ' 2 Gould, 87. 



5 De Geer, ii. 1067. * Huber, 146. 



z 4 



