340 
Psyche 
[December 
dency to follow close upon other workers (tandem running: definition 
by Wilson 1959). They actively face encountered nestmates while ex- 
citedly vibrating their antennae, but without performing the alerting 
movements of a food finder. Excitement and activation in a weaker 
degree is also transmitted to these secondarily encountered ants. In 
both the primarily and secondarily alerted ants, however, the incite- 
ment fades relatively quickly unless new stimuli are provided. 
The food finder ant continues to alert nestmates one after the 
other. When it reaches the nest twigs it passes from one entrance 
hole to another, sometimes briefly entering into the twigs. In this 
situation the recruitment is quantitatively most efficient. Very often, 
however, it returns in the direction of the food after several contacts 
on the road and before reaching the nest. It may turn right onto the 
food bridge or else pass beyond that place and then turn back. It 
Figure 5. 
20 
40 
60 
