The brush mouse may occur, but has not been found on the mountain. The nest looks like a pile of sticks but contains many passages and rooms. The abandoned passages are used by a variety of other animals. Woodrats eat seeds, nuts, and berries. The meadow mouse or vole is abundant in the grassland areas of Mount Diablo.
Voles make runways through the grass.
They feed on grass, seeds, roots, and bark. This gopher, seen throughout Mount Diablo, also digs up lawns and gardens. Gophers feed on roots, grasses, herbs, and seeds. This common red-brown colored squirrel is seen on power lines and trees throughout the bay area. The fox squirrel was introduced into California and has replaced the grey squirrel over much of its range.