On the occurrence and behavior of Japan house mouse Mus musculus in an apartment house group

Abstract

The three species of rats, the Norway rat (Rattus norvegicus), the roof rat (R. rattus) and the Japan house mouse (Mus musculus), are the most common species in houses in Japan. But, in the cities, R. nor. and R. r. are the dominant species and Mus. m. has been rarely found in the building. Recently, an apartment house group was found in the suburbs of Tokyo, in which Mus. sp. was the dominant species in-and out-doors and the ecological studies on the mice were made in this apartment. Collection of mice and rats using snap and alive-traps for three days was made in some buildings and in the field of the site. Six mice (3 females, 3 males) were captured in some households and a female Norway rat was also found in the field. According to the questioning and observations on the mouse injuries, mice were widely distributed over the apartment. Usually, their entrances into the building were small, 10 to 20mm in width, and some improvements may be necessary to prevent their invasion.