ABSTRACT
The orientation of ants has been studied for a long time. Santschi (1911) reported on the homing orientation of Cataglyphis bicolor and Messor barbatus using the sun compass. Many ant species use visual clues for orientation. Workers of Lasius niger rely on visual cues as well as light polarization (Carthy, 1951). Rosengreen (1971) demonstrated that route fidelity occurs in Formica due to a detailed memory of visual cues along the trail. Holldobler (1976) found that the use of chemical trail and visual memory allows accurate homing by Pogonomyrmex species. Holldobler (1980) also demonstrated that workers of Paltothyreus tarsatus are incapable of sky orientation. They employ canopy orientation instead, a more apropriate method for a species that lives in tropical forest. Vilela et al. (1987) demonstrated that Atta cephalotes and Atta laevigata use different homing cues in the following order: 1) presence of chemical trail, 2) visual cues or layout of trail, 3) odor cues on the trail and 4) gravitational cues. Vilela (1983) suggested a different hierarchy for the orientation of Acromyrmex octospinosus, with the odor trail having a more important role in homing.
