ANTS AND THEIR HELPLESS CHILDREN 285 
and when they appear to be playing together, one ant 
is often performing this kind office for another. Still, 
in spite of wandering and resting and cleaning them- 
selves, it is marvellous what an amount of work 
these little creatures do, so that in a short time their 
new domain is adapted for their life. 
It may happen, however, that all does not go 
so smoothly ; the new colony may chance to en- 
croach upon the territory of some other ants' nest, 
and then comes dire disaster ; for no two nations can 
fight more relentlessly for a province or a frontier 
than these little ants do for their plots of ground. 
No sooner does one community find that another 
is taking possession of any part of its domain, or 
has given offence in some way unintelligible to us, 
than the workers pour out by thousands, marching 
close together in battle array, eager for the attack. 
Meanwhile those belonging to the other side advance 
to defend themselves, and when the two armies meet 
they fall upon each other, two by two, taking hold 
with their mandibles, and raising themselves up on 
their hind legs, so that they can turn the abdomen 
under the body. This is in order that they may 
squirt out from the tail that strong acid called formic 
acid, which acts as a poison, so that often the com- 
batants fall dead locked in each other's arms. When- 
ever these ants are excited the scent of formic acid 
is very strong, so that you may smell it in passing 
the nest. 
If one ant succeeds in disabling the other, remain- 
ing unhurt herself, she tries to drag her victim off to 
the nest, there to be killed and devoured. Now, 
although all these ants are exactly alike, each army 
