Fig. 1. Experimental paradigm. (A) Training situation. Ants trained to a feeder located either 5 m, 10 m or 20 m south of the nest entrance were captured at the feeder and transferred to the test field. Filled square, nest; open square, feeder where the ants later were captured and transferred to the test field. (B) Example of a trajectory of an ant transferred from the feeder to the test field. Open circle: point of release; filled circle: correct position of the (fictive) nest; open triangle: end of home vector; filled triangle: center of systematic search (for definition of end of home vector and center of systematic search see data analysis); mesh width of grid was 1 m.