412 
Psyche 
[December 
ubiquitous in eastern Australia, even commonly invading parks and 
gardens. It is readily obtainable, easy of culture, and in general a 
nearly ideal laboratory animal for the study of behavioral patterns 
in that section of the genus in which normal alate females are 
usually lacking. 
In the course of a ten-year study of this species in the laboratory 
and the field, particular attention was paid to the mode of mating of 
the fertilized workers, and of the founding of new colonies. In the 
course of this investigation, numerous observations have been made 
of worker behavior closely resembling the “calling” pattern in 
Leptothorax. The earliest of these observations were recorded 
several years ago (Haskins and Whelden, 1965) but as they have 
been considerably expanded since, and as they seem to “fit” so 
accurately the pattern described for Leptothorax and its congeners, 
it has seemed appropriate to expand the record. 
In R. metallica males are produced irregularly throughout the 
year, both in the laboratory and in the field. They are characteristi- 
cally low-flying, and W. L. Brown, Jr. some years ago observed 
them coursing closely over the ground, and entering the nests of 
other colonies (unpublished observations). 
In laboratory colonies, as earlier described (Haskins and 
Whelden, 1965) groups of workers were observed in September, 
1952, to emerge from the artificial nests and rest quietly grouped 
near their entrances, with head and thorax closely appressed to the 
substrate and gaster raised and arched. At the same time, the sting 
was characteristically exserted. This immobile “pose” was usually 
main-tained only briefly, but in the longest interval recorded, for 
over twelve minutes. It was commonly interrupted eventually by 
other foraging or recently “calling” workers nearby. During this 
process, copulations might occur with recently emerged males, 
although there was no clearly exhibited preference of males for 
“calling” workers over those that were wandering or foraging 
normally. 1 
Since these observations were published, this pattern has been 
observed repeatedly in further colonies of R. metallica housed in 
laboratory nests. The sets of observations shown below are typical. 
They involved three colonies in all, originally collected at Nam- 
'See Holldobler, B. and C. P. Haskins ( Science 195, 793-794) for illustrations of 
this behavior. 
