ANTS, 53 
This formic acid is allied in both its composition and its 
effects upon other animals to the irritant secreted by the 
Common Stinging Nettle, and also to the poison used with so 
much effect by the Wasps and Bees. Those who have not 
realised what formic acid can do might try the effect of 
holding a freshly scratched or pricked finger over an ants’ 
nest just after this has been disturbed. The resulting sen- 
sation will enable them to understand how it happens that 
when an ant has bitten some other small creature with its 
powerful jaws, and has immediately squirted some of its 
formic acid into the wound, the injured animal quickly 
succumbs to the effects of the irritant poison. Ants have 
no stings; but their mode of offensive attack just referred 
to is quite as effectual in its operation as the neater and, so 
to speak, more scientific method adopted by its cousins the 
Wasps. 
Let us now imagine that we go back to an ants’ nest, and 
we will further suppose that the intrusion this time takes 
place in August. The chances are, in that case, that then 
we should see that the disturbed community consists of at 
least two kinds of ants. The majority would still consist of 
these kinds that we saw so busily at work carrying away 
their young ones and repairing the damage to their home. 
The remainder are provided with wings, and seem to con- 
cern themselves much less about domestic calamities, even 
those befalling the young ones, than their wingless fellow- 
lodgers do. Replacing the roof of the house, as before, we 
might afterwards continue to observe the ways of the ants 
for a week or two, and observe what happens. 
Some fine morning in August, after the sun has dried up 
all the dew, we may thus find that a vast army of the 
winged ants will sally forth from the nest and begin to 
mount into the air. By some instinctive impulse, the 
nature of which is yet unknown, all the neighbouring winged 
ants of the same species do the like, with the result that 
the air in places may seem full of them. The swarms accumu- 
late to such an extent in some cases, that the motion of 
their wings in the bright sunshine has been said to give the 
impression of the movements of a large body of smoke; and 
