1967] 
Talbot — Polyergus 
301 
back and forth. Sometimes they retreated from one place to gather 
at another. The actual beginning of a foray was not certain until 
a line of ants extended a foot or more from the nest. Once a trail 
began, ants drained off from other parts of the nest so gradually that 
the front line might be as far as 8 feet away before the last got 
started ; but soon the ants condensed to a group 2 to 4 feet long and 
6 to 8 inches wide. Once a raiding column was formed, it moved 
fast — about 3 feet a minute — but always the ants alternated run- 
ning back and forth and from side to side with the forward move- 
ment, so there were never any consistent leaders to the group. 
The speed and compactness of the column was usually maintained, 
but sometimes the column widened to 10 or 12 inches, especially when 
loose leaves were being investigated. But, while a few ants might 
search for openings along the way, the main column kept moving 
steadily forward with no hesitation, following what seemed to be an 
obvious trail to a definite objective. Usually they arrived precisely 
at a nest to be raided. Sometimes they missed it by 2 to 10 inches. 
Once the spot was reached, all of the ants began searching every crev- 
ice in a frenzied fashion until the nest entrance was found. If the com- 
pact mass of workers did not find the entrance immediately, they 
began spreading out in widening circles. If the located entrance was 
open, they poured down it; if it was barricaded with pebbles and 
soil, they might dig for as much as 3 to 7 minutes before gaining ad- 
mittance. Most of the F. p. nitidiventris colonies in the raided area 
kept their nests barricaded. Workers usually did not try to defend 
the nest, nor did they take away brood. Sometimes a worker was 
carried out and released ; sometimes one ran out by itself, but there 
was seldom any fighting. Once the Polyergus gained entrance to a 
nest, it was only a minute or two until an ant reappeared carrying a 
pupa or larva. Others followed quickly, carrying out loot and start- 
ing for home. They returned by the same general path that they had 
taken in coming, each ant picking its own way over a 5- to 10-inch 
width. At home the ants entered the nest with their brood (at the 
Lawn Nest they sometimes piled it up for the F. p. nitidiventris 
workers to carry down). 
When conditions were right, a second raid would take place. 
Sometimes the second column started before all the first ants had 
come in ; sometimes there was a delay while they milled about the 
nest. Occasionally the second raid began with ants pouring out of 
the nest after all had gone below ground. On rare occasions a third 
raid took place; and once, after a successful raid, 2 columns started 
out in different directions at exactly the same time. 
