1981] Topoff, Rothstein, Pujdak, & Dahlstrom — Army Ants 153 
messor brood we made use of the panic-alarm behavior that this 
prey species exhibits when raided by army ants. Accordingly, we 
released several hundred adult i V. nigrescens into the nest entrance 
of Novomessor, and aspirated the larvae and pupae that were 
removed from the nest by their own adult workers. Whenever 
colonies were artificially fed, food was given at the start of raiding in 
the evening, while the column was within 2 m from their bivouac. If 
columns emerged from more than one exit hole, booty was placed at 
the front of each ant column. 
Results 
The raiding and emigration activities of colony no. 1 are summar- 
ized in Table 1. This colony was found on July 11, late in its 
nomadic phase. It became statary on July 13, after settling into a 
kangaroo rat mound ( Dipodomys spectabilis). On the third statary 
night, the colony conducted a 3-m long shift to the other side of the 
mound. A statary shift differs from a nomadic emigration in that it 
is neither preceded nor followed by raiding. It consists instead of a 
single, unbranched column, and is presumably caused by a dis- 
turbance at the old site. For the next 13 statary days, the colony 
remained at the same bivouac, and staged either brief (1-3 hr) or no 
predatory raids. On statary day 17, however, the colony conducted a 
longer shift to an adjacent mound. During the move, we observed 
that all of the pupae were deeply pigmented, and that a few callows 
were being transported by mature adults to the new site. As a result 
of detecting the onset of eclosion, we started artificial feeding of the 
colony on the next night (July 30), and continued to supply food for 
a total of six consecutive nights (Table 1). 
Each evening, a basal column "appeared on the surface shortly 
after sunset (1800-1900 hr). As soon as the ants contacted the food, 
the process of mass recruitment resulted in a sharp increase in ant 
traffic out of the nest. On the days of heaviest feeding, when more 
than 30 g of booty were provided, the army ants required several 
hours to transport it back to the bivouac. The colony occasionally 
put out additional raiding columns later each night, but all captured 
booty was promptly brought back to the original bivouac, and no 
emigrations occurred. On the afternoon of August 5, the study area 
received 14 mm of rainfall between 1400-1550 hr. The overcast sky, 
coupled with cool temperatures late in the afternoon, enabled the 
