From above the ground, a burrow may look like merely a simple hole in the ground. However, these burrows are often very elaborate. One group of scientists found six females and five males living in a single burrow that consisted of a total of 741 feet of tunnels and thirty three different openings.

During colder months, California Ground Squirrels go into a true hibernation. Unlike bears, who enter a long sleep, the squirrels actually enter a state of inactivity. In this state, their heart rate slows by 90% and their respiratory systems slows down so much that they often take a breath only once every few minutes.

During hibernation, ground squirrels will wake up for a very short period of time every five days or so. The squirrels wake up to eat the food that they have stored in special chambers of the burrow and will then relieve themselves in a special "bathroom" chamber.