2SS HYMENOPTERA. 
all the species of ants ; the nest is of 
great size, and divided into stories, placed 
one over the other, like those of a house, 
and each containing a suite of large apart- 
ments, besides smaller rooms, or cells : 
some nests have been known to contain 
twenty stories above-ground, and twenty 
more under-ground. These ants cannot 
bear much heat ; in dry weather, when 
the sun shines brightly, they remain 
at home, shutting their doors to keep 
out the heat, and placing sentinels to 
prevent the intrusion of other insects : 
but on the first shower of rain they re- 
sume their work. Some are skilful ma- 
sons, and build with the earth, which 
is brought to them by others, who are 
employed in mining and digging ; and 
when the structure is of the requisite 
height they strengthen it by adding but- 
tresses at certain distances all round the 
walls. The ceilings of the large apart- 
ments, which are often two inches across, 
are supported by pillars of clay; the 
smaller chambers are vaulted, and nothing 
