206 
Psyche 
[Vol. 94 
wood-, grass-, or leaf-litter on the surface, covering these with a thin 
layer of soil and feeding beneath this protective cover. Chemical 
cues contained in fresh soil sheeting of these two termite genera are 
detected by scout ants of Megaponera foetens (Longhurst and 
Howse, 1978); this effect was not investigated in the present study. 
Foragers of O. berthoudi broke open the soil sheeting or looked for 
natural openings. Termites were captured one by one; the prey was 
held in the ants’ mandibles, impaled on the sting and flung under- 
neath the body to the rear. After catching up to 15 termites in this 
way, the foragers gathered most of the semi-immobilized bodies and 
stung them once again. They packed the termites between their 
mandibles and brought them back to the nest. O. berthoudi also 
preyed on Hodotermes mossambicus, which are grass-harvesters on 
the surface, and which sporadically exit in small groups from 
underground galleries. The ants located these visually, and captured 
single termite workers which were immobilized with the sting. Suc- 
cessful foragers only remained inside their nest for a short while 
before they reappeared (in laboratory nests they leave their prey in 
the entrance chambers), and revisited the same locations. Foragers 
were often found with missing limbs, and such injuries are presuma- 
bly sustained during hunting. 
Recruitment never occurred, and single foragers independently 
exploited a food source until it was exhausted. Social facilitation 
was observed in laboratory nests however; the return of successful 
foragers induced others to go out and hunt, but to no particular 
location. The lack of cooperation between hunters is associated with 
the absence of trails in this species. The distinctive trail-laying gait 
was never observed, and simple experiments showed that foragers 
do not become disoriented when soil ahead of them is disturbed. 
Instances of tandem running were never seen. Some kind of discrete 
marking was sometimes observed however. Workers stood momen- 
tarily still and rubbed the ventral tip of their gaster sideways over 
objects lying on the ground (e.g. pebbles, dead leaves, sticks,. . .); 
marking was never done directly onto the bare ground. This behav- 
ior was especially conspicuous around nest entrances after rain, and 
also occurred when some foragers walked away from their nests. We 
suggest that ants which are unfamiliar with a new area outside their 
nests lay these marks and then use them as personal orientation cues 
