388 THE INSECT WORLD. 



Ants are also very fond of a peculiar liquid which the plant-lice 

 secrete from a pouch in the abdomen. When they have got posses- 

 sion of a plant-louse, they excite it to secrete this liquid, but without 

 doing it any harm. They carry the plant-lice into the ant-hill, or 

 into private stables. There they keep them, give them their food, 

 and suck them. We have already mentioned these curious relations 

 which are established between ants and plant-lice.* Fig. 367 shows 

 an ant thus occupied. The Gallinsecta also furnish the ants with 

 sugary liquids. 



During the cold of winter the ants sleep at the bottom of their 

 nests, without taking any food. A small number of species only hold 

 out through the severe season, by shutting themselves up in the ant- 

 hill with a number of plant-lice. It is thus that they pass the winter 

 with a supply of food. We must mention, however, that in warm 

 countries the ants do not hybernate. 



We have just described ant society during the quiet periods, when 

 peace reigns supreme ; but they are not more exempt than other 

 animals from the necessities and dangers of war. They have a great 

 many enemies among the population of the woods ; they must, then, 

 be prepared to repel their attacks. They display in that the most 

 scientific resources of the military art applied to defence. 



It is almost needless to say that the sentinels are, at all times, 

 posted at a reasonable distance from the ant-hill, to observe the 

 environs. When the fortress is unexpectedly attacked, whether by 

 large insects, Coleoptera for instance, or by the ants from a neigh- 

 bouring nest, these vigilant sentinels immediately fall back and give 

 the alarm to the camp, not, however, without having boldly confronted 

 the enemy and opposed to him an honourable resistance. Having 

 re-entered the nest in all haste, they precipitate themselves into the 

 passages, tapping with their antennae all the ants which they meet, 

 and thus spreading the alarm in the city. Very soon the agitation 

 has become general, and thousands of combatants sally forth from the 

 citadel, ready to repel the attack and make the enemy bite the dust. 



The possession of a flock of plant-lice is sometimes a subject of 

 discord, and becomes a casus belli between two neighbouring ant-hills. 

 But, usually, the war has for its object to make prisoners in other 

 nests, and to carry oft' part of the inhabitants as slaves. This is the 

 origin of mixed ant-hills, which, independently of their natural 

 founders, contain one or two foreign species, helots whom the con- 

 querors have taken away from their birth-place, to make of them 



* See the Order Hemiptera^ mpra. — Ed. 



