180 
Psyche 
[Vol. 91 
Defense 
P. scahriusculus relies almost exclusively on its thick exoskeleton, 
with cephalic scrobes to shield the antennae, to discourage enemies 
and predators. In response to real or supposed threats (other ants, 
freshly killed flies, seeds, flowers, pollen, etc.), workers lowered 
their heads, contacted the object, and pushed. The workers also 
nipped as best they could with their small, blunt mandibles. P. 
scahriusculus was ineffective in coping with enemy ants in the open. 
One colony in a petri dish took 12 hours to clip the legs off a 
Pseudomyrmex sp. worker placed in the nest. Presumably bulldoz- 
ing would be more effective inside a twig nest in preventing tres- 
passers from entering and nipping would be more effective where 
the enemy could be pinned against the walls of the narrow 
passageways. 
Ley movements 
Another behavior not included in the repertoire is miscellaneous 
leg movement. When ants were inactive, standing quietly in posi- 
tion, often 1, 2, or, rarely, 3 of their legs might be moving. Most of 
the movement was made by the tibia and tarsus, which were swung 
as a unit, while the femur stayed in place. Often, the femur was 
flexed and also participated in the movement. About 60% of the 
time the movement involved one of the rear legs, 30% a middle leg, 
and 10% a front leg. The behavior was observed in queens as well as 
workers. 
QUEENS 
Number of queens 
P. scahriusculus has multiple queens. The colony observed in this 
study contained, at the time of collection, 6 dealate queens and 62 
workers (8.8% queens). After the study was terminated, the colony 
was preserved in alcohol. Subsequent dissection showed that all 6 
queens had fully developed ovaries. In addition, 3 queens (#1, #4, 
and #6) contained at least one egg large enough to fall in the size 
range of viable eggs. Two fragments of other colonies contained 4 
queens with 40 workers (9. 1%) and 1 queen with 17 workers (5.5%). 
A large colony collected in November, 1982, contained 72 workers 
with 27 queens (27%). In this colony, many of the queens had unex- 
panded, crumpled wings indicating that they had been produced 
within the colony and were not primary, founding queens. 
