ON THE HABITS OF ANTS. 43 



species, as our small yellow meadow ants, the autumn larvae remain 

 with comparatively little change throughout the winter. It is much 

 more difficult to ascertain the length of life of the perfect insect, on 

 account of their gregarious habits, and the difficulty of recognizing 

 individual ants. It has, however, generally been supposed that 

 they live about a season, and this is probably the case ; but I have 

 still some workers of F. cinerea, which I captured at Castellamare 

 in November, 1875, and some of F. sanguinea and F. Jusca since 

 September in that year. They must now, therefore, be at least a 

 year and a half old. I have also some queens of F. fusca which 

 have been with me since December, 1874, and still seem in perfect 

 health. If they lived mucli longer, and could compare their ex- 

 periences, ants would, from their immense numbers, even in temper- 

 ate regions, contend with mankind on no such very unequal terms. 



The behavior of ants to one another differs very much according 

 as they are alone or supported by numerous companions. An ant 

 which would run away in the first case, will fight bravely in the second. 



It is hardly necessary to say that, as a general rule, each species 

 lives by itself. There are, however, some interesting exceptions. 

 The little Stenamma Westwoodii is found exclusively in the nests of 

 the much larger F. riifa and the allied F. pratensis. We do not 

 know what the relations between the two species are. The Stenammas, 

 however, follow the Formicas when they change their nest, running 

 about among them and between their legs, tapping them inquisi- 

 tively with their antennae, and even sometimes climbing on to their 

 backs, as if for a ride, while the large ants seem to take little notice 

 of them. They almost seem to be the dogs or rather cats of the 

 ants. Another small species, Solenopsis fugax, which makes its 

 chambers and galleries in the walls of the nests of larger species, is 

 the bitter enemy of its hosts. The latter cannot get at them, 

 because they are too large to enter the galleries. The little Sole- 

 7iopsis, therefore, are quite safe, and, as it appears, make incursions 

 into the nurseries of the larger ant, and carry ofi* the larvse as food. 

 It is as if we had small dwarfs, about eighteen inches to two feet 

 long, harboring in the walls of our houses, and every now and then 

 carrying otf some of our children into their hoi'rid dens. 



Most ants, indeed, will carry oif the larviB and pupae of others if 

 they get a chance ; and this explains, or at any rate throws some light 

 upon, that most remarkable phenomenon, the existence of slavery 

 among ants. If you place a number of larvae and pupae in front of 

 a nest of the horse ant, for instance, they are soon carried off; and 

 those which are not immediately required for food remain alive for 

 some days, though I have never been able to satisfy myself whether 

 they are fed by their captors. Both the horse ant and the slave ant 

 {F. fusca) are abundant species, and it must not unfrequently occur 

 that the former, being pressed for food, attack the latter and carry off 



