THE FORMICIDA. 199 
They may be found in woods where the underwood is not very 
dense, and they constitute slightly elevated and rounded little 
patches of earth at the foot of oaks for instance, but sometimes 
they are of considerable width and length. The surface of the 
hills is made up of a mass of little pieces of wood, bits of straw, 
flints, grains of wheat or of oats, and of earth, and it does not 
require much trouble to become aware that they are all arranged 
with a purpose, although they appear to be laid about confusedly. 
If a portion of the roof be broken down a crowd of agitated ants 
comes to the breach, and begins to repair the mischief at once, 
working with the most intelligent and persevering determination. 
Worker Female. 
THE RED ANT. 
(Formica rufa. ) 
A glimpse may be had of the interior of the building whilst 
the roof is being reconstructed. Sometimes the nest descends 
to a considerable depth, and it will be noticed that the ants 
have had to clear out and excavate portions one after the 
other, as the swarm increased in numbers. It appears to be 
made up of a tangle of pieces of wood all about the same size, 
and which appear to be piled up anyhow; but by examining the 
confused mass with some attention it will be noticed that the 
morsels of wood are so arranged that they form chambers, 
galleries, and more or less irregular tracks or runs. Moreover, 
they are so arranged as to permit a free passage in every part of 
the nest. In fact, the pieces of wood are disposed after a definite 
plan, and with much care. Those in the lowest part of the ant’s 
