20 ARCHITECTURE OF ANTS, 
ants are endowed with great sensibility, 
and know the degree of heat best adapted 
for their young. The ant-hill contains 
sometimes more than twenty stories in 
its upper portion, and at least as many 
under the surface of the ground. By 
this arrangement the ants are enabled, 
with the greatest facility, to regulate the 
heat. When a too burning sun over- 
heats their upper apartments, they with- 
draw with their little ones to the bottom 
of the ant-hill. The ground-floor becom- 
ing, in its turn, uninhabitable, during 
the rainy season, the ants of this species 
transport what most interests them to the 
higher stories, and it is there we find 
them more usually assembled with their 
pupz and eggs, when the subterranean 
apartments are submerged.* Having as- 
* De Azara informs us, that during the inunda- 
tion of the low districts in South America, when the 
ant-hills, which are usually about three feet in 
height, are completely under water, the ants avail 
themselves of an ingenious contrivance, to pre- 
vent their being carried to any distance from their 
