274 SOCIAL BEHAVIOUR 
does not agree with the beetle larvae. The ants are in the 
habit of digging up their own kind, and lifting them out and 
cleaning them during their metamorphosis : they do this also 
with the. beetle larvee, with fatal results; so that only those 
that have the good fortune to be forgotten by the ants com- 
plete their development.” * 
Aphides, or plant-lice, yield to the solicitations of ants, 
which stroke them with their antenne, by emitting a drop of 
sweet and viscid secretion, and it appears that the caress of the 
ant is the natural stimulus for the emission of the drop. Not 
only, however, do the ants go forth in search of aphides in 
their natural haunts, they bring them to the neighbourhood of 
the nest, and may even impound them by building a wall of 
earth round and over them. Huber stated that ants collected 
the eggs of the aphides and tended them in their nests, and 
the accuracy of the observation has been shown by Lord 
Avebury and others. “The aphid eggs are laid early in 
October, on the food plant of the insect. They are of no direct 
use to the ants, yet they are not left where they are laid, 
where they would be exposed to the severity of the weather 
and to innumerable dangers, but brought into the nests by the 
ants, and tended by them with the utmost care through the 
long winter months until the following March, when the young 
ones are brought out and again placed on the young shoots of 
the daisy.” { Dr. McCook noticed that ants, returning from 
the trees on which aphides abounded, fed others near the nests, 
and he regarded this as a case of division of labour, the 
foragers obtaining food for the nurses which remained in or 
near the nest. 
A further division of labour, carried to lengths which seem 
almost absurd, is found in the honey-pot ant of the United 
States and Mexico. The juice on which these ants feed is 
obtained from an oak-gall. Foragers go forth at night and 
return distended with the sweet fluid, and, having fed the 
* Sharp, op. cit., p. 226. 
+ Lord Avebury (Sir John Lubbock), quoted in Romanes’ “ Animal 
Intelligence,” pp. 62, 63. 
