The Japanese dormouse (Glirulus japonicus) is a species of rodent in the Gliridae family. It is the only species in the genus Glirulus. It is endemic to Japan. Its natural habitat is temperate forests. In Japanese it is called Yamane (山鼠). It has the special ability of running at great speed upside down, underneath branches. Its main food is nectar or pollen, although nursing females will eat small insects.