But, I found this interesting paper by non other than ‘the duo’, Holldobler and Wilson. Of the several interesting points in this article is that when the major workers cannot cross gaps to reach a terrain, they build bridges, to which other workers are visually attracted. However once the chains are formed, workers lay trail pheromones on this ‘bridge’ to recruit nestmates. The five different recruitment systems used by the African Weaver ant, Oecophylla longinoda as documented in this article are:
(a) recruitment to new food sources, mediated by odor trails produced from the rectal gland, coupled with tactile stimuli during mouth-opening, antennation, and head-waggling
(b) recruitment to new terrain, mediated by odor trails produced from the rectal gland and tactile stimulation through antennation
(c) emigration to new sites
(d) short-range recruitment to territorial intruders, during which the terminal abdominal sternite is maximally exposed and dragged for short distances over the ground to release an attractant from the sternal gland
(e) long-range recruitment to intruders, mediated by odor trails from the rectal gland and by antennation and intense body jerking
There are some fantastic sketches and close up photographs of these ants in the article.
Holldobler B and Wilson EO. 1978. The multiple recruitment systems of the African Weaver Ant, Oecophylla longinoda (Latreille) (Hymenoptera: Formicidae). Behav Ecol Socio 3: 19-60.