56 THE ARGENTINE ANT. 
Many permanent nests are located in the tops of trees, in rotten 
branches, or in places where borers or termites have been working. 
In rotten logs the ants will nearly always utilize old borer or termite 
tunnels for their nests, but do not appear to do any boring for them- 
selves. 
The facility with which entire colonies move is sometimes amazing. 
If a nest is disturbed the workers will frequently move all stages and 
establish another nest in a fresh location in the course of a very few 
minutes. 
UNDERGROUND NESTS. 
The ants seldom burrow to any great depth in the ground. The 
exceptions to this occur during hot, dry weather in the summer or 
during particularly cold spells in the winter. In the dry spells they 
evidently work downward in an endeavor to secure sufficient hu- 
midity for the young, while in the wintertime they sometimes go 
deep into the soil for the sake of protection from the cold. The 
deepest burrows which we have measured have been 14 inches in 
depth, but they usually average from 4 to 10 mches under normal 
conditions. These deep burrows are usually located at the foot of 
tree trunks, or under the ridges in cane, cotton, or corn fields. 
Under more favorable circumstances, however, the underground 
galleries average from 1 to 4 inches in depth. In summer time the 
ants appear to do as little excavating as possible and seem to limit 
their efforts to excluding light and water. When the nests are 
located above ground, under boxes, boards, stones, etc., very little 
soil is used, and this is utilized in closing holes, etc., to keep out 
light and drafts. 
WET-WEATHER NESTS OR SHEDS. 
In wet situations or after heavy rains, when the ground has become 
soaked with water, the ants construct curious honeycombed structures 
around the bases of tree trunks. These are made of a great number 
of fine, loose particles of soil, usually supported by grass stems or 
loose leaves. They vary from one-half inch to as much as 5 inches 
in height, and sometimes cover an area of several square feet. They 
are built with great rapidity by the workers, and are extremely frail, 
falling in at the lightest touch. As a result of this weakness these 
nests disappear after a few days of dry weather, or are washed away 
by showers. They consist of a maze of covered galleries, in which 
large numbers of the larvae and pupae are placed. Their purpose 
appears to be to afford protection to the young stages until the 
ground gets dry enough for the underground galleries to be 
reoccupied, or they may be used to dry and ' k air" stages which 
have become wet, the loose construction permitting a liberal circula- 
tion of the air through the walls and ceilings. (See PL V.) 
