What do ants and light rays have in common when they pass through lenses?

(Laboratory of Behavioral Ecology and Evolution at Seoul National University) Foraging trails of ants across a lens-shaped substrate that slows them (Velcro) down diverge away from the " lens " center more for the convex than for the concave lens, similar to the behavior of light.
Source: EurekAlert! - Social and Behavioral Science - Category: International Medicine & Public Health Source Type: news