1987] Topoff, Bodini, Sherman, & Goodloe — Polyergus 263 
procedure required two persons, the first to constantly monitor the 
scout’s path, and the second to place the numbered markers. Using a 
compass and a rolling measuring wheel, a map was made depicting 
the scout’s path. 
Results 
During the three-week period of this study, 18 scouts were 
followed on 12 different days. Of these 18 scouts, five were tracked 
only on their outbound trip to a target colony of Formica gnava. 
For three other scouts, we succeeded in following their return trip as 
well. On five occasions, our tracking was abruptly halted when the 
scout was seized and killed by a spider. The remaining five scouts 
disappeared beneath the leaf litter before reaching a target colony. 
The outbound paths of all scouts consisted of two distinct phases. 
Because of the essential similarity in movement among the scouts, 
the route illustrated in Figure 1 can serve as a typical example of 
scouting behavior. The target Formica nest on this day was located 
approximately 40 m to the west of the Polyergus nest. Phase one of 
scouting began when individuals left the swarm of ants circling 
around the nest, and moved in a relatively constant compass direc- 
tion. For the scout on the afternoon of July 23, this straight run 
extended about 30 m to the west (the range for phase-one scouting 
on all days was 25-45 m). During this phase the scouts ran continu- 
ously, without stopping to search for Formica colonies. The second 
phase of scouting involved a qualitatively different pattern of 
movement, with scouts changing direction after running small dis- 
tances over all compass directions. More importantly, it was only 
during this second phase that scouts periodically stopped and 
searched beneath rocks and patches of leaf litter. On July 23, this 
searching phase extended the scout’s path for an additional 10 m to 
the west, with the north and south displacement combined covering 
about 14 m. Thus the searching phase of this particular scout 
covered an area of approximately 140 m 2 . 
A representative map of the complete sequence of successful 
scouting, followed by a slave raid, is illustrated in Figure 2. To 
clarify the distinctness of the paths, the erratic phase-two move- 
ments of the scout were replaced by a line extending from the end of 
the phase-one run, directly to the target nest. The most significant 
finding here is occurrence of three non-overlapping routes for the 
outbound run, return trip, and slave raid respectively. After locating 
