Figure 2.

Artificial nest sites used during the field experiments. (A) Photograph of an artificial nest site made of a woodblock (see Figure 1). Such nest sites made of woodblocks are readily accepted by acorn ants of the genus Temnothorax. (B) Entrance to an artificial nest site modified by the Temnothorax crassispinus ant colony using sand and soil. (C) Artificial nest sites made of woodblocks during the field experiment. During this study, the artificial nest sites were located in a beech-pine forest with a few oaks, about 2–6.5 m from the edge of the forest.