148 HYMENOPTERA CHAP. 



material. Our figure is taken from a specimen (tor which we 

 are indebted to Mr. E. E. Green) that was captured in the act 

 of bearing a larva. 



Formica rufa, the Red-ant, Wood-ant, or Hill-ant, is in this 

 country one of the' best-known members of the Formicidae. It 

 frequents woods, especially such as are composed, in whole or 

 part, of conifers, where it forms large mounds of small sticks, 

 straws, portions of leaves, and similar material. Although at 

 first sight such a nest may appear to be a chaotic agglomeration, 

 yet examination reveals that it is arranged so as to leave many 

 spaces, and is penetrated by galleries ramifying throughout its 

 structure. These mound-nests attain a considerable size when the 

 operations of the industrious creatures are not interfered with, or 

 their work destroyed, as it too often is, by ignorant or mischievous 

 -persons. They may reach a height of three feet or near it, and 

 a diameter of twice that extent. The galleries by which the 

 heaps are penetrated lead down to the earth below. From the 

 mounds extend in various directions paths constantly traversed 

 by the indefatigable ants. M'Cook observed such paths in the 

 Trossachs ; they proceed towards the objects aimed at in lines 

 so straight that he considers they must be the result of some 

 sense of direction possessed by the ants ; as it is impossible to 

 suppose they could perceive by the sense of sight the distant 

 objects towards which the paths were directed : these objects in 

 the case M'Cook describes were oak-trees up which the ants 

 ascended in search of Aphides. 



M'Cook further observed that one of the oak-trees w y as reached 

 by individuals from another nest, and that each of the two parties 

 was limited to its own side of the tree,, sentinels being placed on 

 the limits to prevent the trespassing of an intruder ; he also 

 noticed that the ants saw an object when the distance became 

 reduced to about an inch and a half from them. This species is 

 considered to be wanting in individual courage ; but when acting 

 in combination of vast numbers it does so with intelligence and 

 success. It does not make slaves, but it has been observed by 

 Bignell and others that it sometimes recruits its numbers by 

 kidnapping individuals from other colonies of its own species. 

 Its nests are inhabited by forty or fifty species of guests of various 

 kinds, but chiefly Insects. Another ant, Jlyn/iicd laevinodis, 

 sometimes lives with it in perfect harmony, and Formicoxenus 



