170 
Psyche 
[March 
from, the worker traffic. Columns occasionally branch and have been 
observed as long as ca. 2 m. 
Irregular craters of soil, up to 8 cm in diameter and i cm high, 
are often thrown up around the holes during periods of surface 
activity. Ground-level runways radiating from the hole may be 
bridged over to transform a crater into a rough pile of soil 2 to 3 cm 
high. Since individuals of this species are relatively small (length 
of soldier, 3.0 mm; of worker, 4.5 mm), access holes as large as 
5 mm in diameter probably provide for efficient, emergency re-entry 
of large numbers of foragers in a very short time. Workers have 
been observed to close the exposed holes shortly after the conclusion 
of surface activity and, although a few soldiers remain in and around 
the hole during closure, none was ever left outside. The same holes 
are apparently used repeatedly, at least for periods of several weeks. 
The high proportion of soldiers in the foraging groups indicates 
the relative importance of this caste in those species of termites which 
routinely forage on exposed trails. The four combined groups col- 
lected from colonies beneath stones contained 545 individuals with a 
soldier rworker ratio of 1:3.82 (20.7% soldiers). Three combined 
foraging groups contained 1,549 individuals with a soldier :worker 
ratio of 1:1.23 (44-9% soldiers). A single foraging group of 230, 
perhaps recently organized, had a ratio of 1 soldier to 0.40 worker 
(71-3% soldiers). 
Soldier behavior. — Whenever the laboratory group of soldiers and 
workers was disturbed by jarring or removing the cover of their 
container, several soldiers, with antennae raised and waving, congre- 
gated on the edges of objects and on elevated vantage points. In- 
dividual workers of the ant, Pheidole desertorum (ca. 3.5 mm long), 
introduced into this situation were quickly fired on at very close 
range by several soldier termites in rapid succession. The appendages 
of such victims were almost completely immobilized, within 10 sec or 
less, by the viscous, glue-like threads thrown over them. 
Further details of soldier defensive behavior are based on observa- 
tions made during encounters with living ant workers fixed to glass 
slides. Although blind, the soldiers presumably orient toward such 
threats by olfactory or auditory cues. An alerted soldier closes rapidly 
on any potential target and may actually touch it for an instant with 
its antennae before firing — from a distance of ca. 0.5-3.0 mm). As 
it fires, it may jerk forward or backward, in position, and may or 
may not then oscillate to-and-fro one or more times. This apparently 
insignificant bit of behavior greatly enhances the effectiveness of the 
