1967] 
Talbot — Polyergus 
309 
at a colony 286 feet away. The nearest colony nested only 15 feet 
from the Polyergus nest. During June the ants tended to raid nearby 
colonies; 20 raids averaged 56 feet per raid with a range of from 
15 to 128 feet. By July they had to go farther afield to find new 
colonies. Eighteen raids averaged 103 feet and ranged from 18 to 
286 feet. In August some raids were to distant colonies, and some 
were reraids of those nearby. Fourteen raids averaged 72 feet, rang- 
ing from 17 to 213 feet. The 2 September raids were short — 27 
and 43 feet. 
NUMBER OF COLONIES RAIDED 
During both 1964 and 1965 a numbered stake was placed at each 
raided colony. In 1964, 17 different colonies were raided in the 23 
successful raids seen. In 1965, in the 29 successful raids observed, 
20 different colonies were visited. In 1965, the ants found only 2 
colonies where they had been the year before; but they located 5 
others 3 to 9 feet from a 1964 stake. This would seem to indicate an 
unusual amount of moving on the part of F. p. nitidiventris colonies, 
a behavior pattern which was probably instigated by the raids. This 
moving perhaps accounts for the fact that some unsuccessful raids 
were to what seemed to be obvious nest sites which had been recently 
deserted. 
Reraiding of colonies was common practice. One colony only 24 
feet away was known to have been raided on July 22, August 26, 
and September 3 of 1964 and again on June 20 (2 raids) and June 
25 of 1965. During 1964, one colony was known to have been raided 
4 times, one 3 times, and one twice. During 1965, 5 colonies were 
robbed twice and one 3 times. It would seem that, within a raiding 
season, most of the colonies would be visited more than once. The 
total number of colonies available may not have been more than about 
25. This multiple raiding probably kept the colonies so depleted that 
they could not gather numbers enough to produce winged forms. 
Since Polyergus colonies tend to stay in one place for a number of 
years, they probably do not completely destroy F. p. nitidiventris 
colonies; but they may gradually diminish them to the extent that 
the Polergus colony cannot make a living and must move. 
RAIDS WHICH ENDED IN FAILURE 
Occasionally a raiding group, typical in all respects, failed to find a 
colony. This seemed to be the result of misinformation on the part 
of a scout, because the raiding forces were as large as usual and the 
spots they stopped at were just as definite. The usual routine was 
