The desert ant Cataglyphis fortis primarily feeds on dead insects that are sparse and unevenly distributed in their environment. A single forager can carry a small dead insect back to the nest without aid. As dead insects are typically found as individuals and not in groups, foragers locate food as individuals, rather than cooperatively. This allows the foragers as a group to cover a wide area.
To aid in locating food, the ants orient to odors emanating from dead insects. A forager leaving the nest will typically head in a direction to a point suitably distant from the nest. The forager will then move in a direction that is perpendicular (crosswind) to the wind. Odors travel in a plume in a general downwind direction. By moving across the wind, a forager increases its chance of detecting food odor. If food odor is detected, the ant will orient upwind until the source is reached.
Matthew Collett1 and Ring T. Carde. Navigation: Many Senses Make Efficient Foraging Paths. Current Biology Vol 24 No 9 R362-4.