[3] The squirrel's upper parts are mottled, with the fur containing a mixture of gray, light brown and dusky hairs.

[9] California ground squirrels are often regarded as pests in gardens and parks, since they eat ornamental plants and trees.

They commonly feed on seeds, such as oats, but also eat insects such as crickets and grasshoppers, as well as various fruits.

[7] California ground squirrels use their cheek pouches to store more food than can be consumed in one sitting for a later date.

They are considered to be mostly herbivorous, with seeds, grains, nuts, fruits, and sometimes roots constituting most of their diet.

[12] In a study published in December 2024, California ground squirrels were observed hunting and eating voles.

Interdisciplinary research at the University of California, Davis, since the 1970s has shown that the squirrels use a variety of techniques to reduce rattlesnake predation.

[16] When hunting, rattlesnakes primarily rely on their pit organ, which detects infrared radiation.

The hot tail-swishing appears to convey the message "I am not a threat, but I am too big and swift-moving for it to be worth trying to hunt me."

They also can use their tail-waving to signal to other ground squirrels in the area that a rattlesnake or other predator has recently been spotted.