harvest mouse

noun

1. an Old World field mouse, Micromys minutus, that builds a spherical nest among the stems of grains and other plants.
2. any of several New World mice of the genus Reithrodontomys having similar habits.

noun

1. a very small reddish-brown Eurasian mouse, Micromys minutus, inhabiting cornfields, hedgerows, etc, and feeding on grain and seeds: family Muridae
2. American harvest mouse any small greyish mouse of the American genus Reithrodontomys: family Cricetidae