The San Joaquin Pocket Mouse vocalizes with low grunts, growls, and squeals, and communicates aggression by tooth-chattering. This species will consume earthworms and soft-bodied insects, but its diet is mainly very tiny seeds of grasses, forbs, and shrubs. Learn more about the Perognathus inornatus, more commonly known as a San Joaquin Pocket Mouse, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.