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In this study, we conducted a field survey in Aichi Prefecture, central Japan, to clarify whether rodent activity is affected by the presence or absence of dead culms of the dwarf bamboo <i>Sasa borealis</i>, a species characterized by a 120-year cycle of large-scale flowering, seeding, and dying. We found that a relatively larger number of wood mice, <i>Apodemus speciosus</i> and <i>Apodemus argenteus</i>, were caught using Sherman live traps in areas with dead <i>S. borealis</i> culms than in areas lacking the culms, thereby indicating that <i>S. borealis</i> culms, even if dead and leafless, can function as shelters in which the mice can evade predation. However, in the years when <i>A. speciosus</i> was abundant, <i>A. argenteus</i> avoided areas inhabited by <i>A. speciosus</i> and was restricted to areas lacking dead culms, which were devoid of shelter. A feeding experiment using <i>Castanea crenata</i> acorns clearly revealed that a larger number of acorns were foraged by mice in areas containing dead culms. Moreover, in the area with dead culms, the mice preferentially removed sound acorns prior to taking acorns that had been vacated by infesting moth larvae. These findings indicate that the shelter function of dead culms enables mice to carefully select sound acorns, which are nutritionally more beneficial than those that have been infested by moth larvae.