116 
ANIMAL INTELLIGENCE. 
down the outsides of the column, they every now and 
again stop to touch antennae with some member of the 
rank and file, as if to give instructions. When the scouts 
discover a wasp’s nest in a tree, a strong force is sent out 
from the main army, the nest is pulled to pieces, and all 
the larvae carried to the rear of the army, while the wasps 
fly around defenceless against the invading multitude. 
Or, if the nest of any other species of ant is found, a 
similarly strong force, or perhaps the whole army is de- 
flected towards it, and with the utmost energy the innu- 
merable insects set to work to sink shafts and dig mines 
till the whole nest is rifled of its contents. In these 
mining operations the ants work with an extraordinary 
display of organized co-operation ; for those low down in 
the shafts do not lose time by carrying up the earth which 
they excavate, but pass on the pellets to those above ; and 
the ants on the surface, when they receive the pellets, 
carry them, 6 with an appearance of forethought that quite 
staggered ’ Mr. Bates, only just far enough to ensure that 
they shall not roll back again into the shaft, and, after 
depositing them, immediately hurry back for more. 
But there is not a rigid division of labour, although the 
work 6 seems to be performed by intelligent co-operation 
amongst a host of eager little creatures ; ’ for some of 
them act 6 sometimes as carriers of pellets, and at another 
as miners, and all shortly afterwards assume the office of 
conveyors of the spoil.’ Again, as showing the instincts 
of co-operation, the following may also be quoted from 
Bates’s account : — - 
On the following morning no trace of ants could be found 
near the place where I had seen them the preceding day, nor 
were there signs of insects of any description in the thicket ; 
but at the distance of eighty or one hundred yards, I came 
upon the same army, engaged evidently on a razzia of a similar 
kind to that of the previous evening; but requiring other re- 
sources of their instinct, owing to the nature of the ground. 
They were eagerly occupied on the face of an inclined bank of 
light earth in excavating mines, whence, from a depth of eight 
or ten inches, they were extracting the bodies of a bulky species 
of ant of the genus Formica. It was curious to see them crowd- 
ing round the orifices of the mines, some assisting their com 
