The marble burying test is a simple behavioral psychopharmacology task in which rodents, especially rats and
mice, are exposed to glass marbles laying on thick bedding materials. This test has been widely used to assess the effects
of a variety of psychoactive drugs. Although the marble burying test clearly reflects drug efficacy, many aspects of the
behavior itself remain unclear. In the present study, we assessed the effects of different bedding materials and the number
of glass marbles presented on the marble burying behavior of mice (C57BL/6J). Six (bedding materials) × three (number
of glass marbles) factorial experiments revealed that the number of marbles buried correlates closely with the quality of
the bedding material. Our results provide a basic understanding of certain factors that govern marble burying behavior,
which may be applicable to behavioral sciences including psychopharmacology.