BULLETIlSr 965, U. S. DEPAKTMEFT OF AGRICULTURE. 



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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, larvas, 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; 6, male; c, queen. 

 (Greatly enlarged.) 



