BULLETIN 965, U. S. DEPARTMENT OF AGRICULTURE. 
CHARACTERISTICS AND HABITS. 
The Argentine ant, like most other species of ants, forms definite 
colonies or ant communities under the surface of the ground. The 
colony or nest is an elaborate system of galleries and cells, closely 
connected, with usually only two or three openings to the surface. 
Though the galleries may 
cover an area of over 10 
square feet they seldom 
are more than 8 or 10 
inches in depth. Colonies 
are located in places which 
will afford protection from 
excessive moisture and 
give the proper warmth; 
in orchards during the 
winter they are invariably 
on the sunny south side 
of the trees, usually just 
beyond the drip of the 
branches, but in summer 
they are more often on the 
east or north margin. In 
a well-infested orchard 
under cultivation each 
tree has a definite and 
complete colony. The fa- 
vorite places for colonies 
about a residence are un- 
der cement sidewalks, the 
foundations of the build- 
ings, a pile of rubbish, 
the compost heap, or a 
chicken yard. 
The size of the com- 
munity varies greatly with 
the season, the food sup- 
ply, and the age of the col- 
ony. In a normal summer colony the ants will be found in all stages 
of development — eggs, larvae, pupae, workers, males, and females — 
and the colony responds quickly to warm days and an abun- 
dance of food by increasing its numbers. If the colony grows 
rapidly and the food supply warrants it, or if the food supply 
is some distance from the main colony, a new community will 
be started nearer the source of supply by a migration of part 
of the former colony along the trail established. This expan- 
Fig. 3.— The Argentine ant: a, worker; b, male; c, queen. 
(Greatly enlarged.) 
