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[Vol. 94 
Activities around the nest entrances 
Excavation occurred frequently after rain, with soil being brought 
out of the nests to the surface. Nest sanitation was a distinct activity, 
whereby workers came up to the surface and discarded pellets of 
termite remains, as well as empty cocoons. The former consisted of 
jaws, limbs, and other bits of exocuticle, which were all packed into 
a distinctive rough-looking ball. These pellets were carried for 1-5 m 
before being left on the ground; they were never discarded close to 
the nest entrances. Individual cleaners repeatedly dropped their 
pellets in the same place. 
No natural instances of predation on O. berthoudi were recorded, 
but it is suspected that lizards feed on the ants. A number of 
arthropods (beetles, spiders, ant lion larvae) were observed trying to 
steal the termites retrieved by foragers. 
Carrying behavior: adult and brood transfer 
Adult carrying occurred daily and was preceded by a stereotyped 
“invitation behavior”. This involved vigorous antennation and was 
similar to that described by Moglich and Holldobler (1974) for 
Rhytidoponera metallica. However, the carrying posture in O. ber- 
thoudi is completely different (Fig. 1), with the recruit carried on its 
side underneath the other ant. Not all invitation interactions were 
followed by carrying, and the outcome seemed influenced by the age 
and motivation of the participants. 
Adults were carried between existing nests of the same colony. 
Single cocoons, single larvae of all sizes and packets of 3-14 eggs 
were also frequently transported above ground. Males were carried 
between nests during January-February. Different recruiters that 
were active between the same pairs of nests seldom followed the 
same route, and the paths were sometimes strikingly different. This 
is further evidence that the nests are not connected together by 
chemical trails. 
Nest emigration is a frequent occurrence in ponerine ants. Species 
which do not lay chemical trails for social coordination use social 
carrying or tandem running (e.g. Moglich and Holldobler, 1974; 
Fukumoto and Abe, 1983; Holldobler, 1984; Traniello and Holl- 
dobler, 1984; Fresneau, 1985). Both these primitive recruitment 
techniques are preceded by the same invitation behavior, and in 
Pachycondyla obscuricornis they are used alternatively to recruit 
