California ground squirrels live in burrows which they excavate themselves. Some burrows are occupied communally but each individual squirrel has its own entrance. Although they readily become tame in areas used by humans, and quickly learn to take food left or offered by picnickers, they spend most of their time within 25 m (82 ft) of their burrow, and rarely go further than 50 m (160 ft) from it. In the colder parts of their range, California ground squirrels hibernate for several months, but in areas where winters have no snow, most squirrels are active year-round. In those parts where the summers are hot they may also estivate for periods of a few days.