The California kingsnake is primarily diurnal, but may become increasingly nocturnal during periods of particularly hot weather. In the winter, they retreat underground and enter a hibernation-like state called brumation. When disturbed, California kingsnakes will often coil their bodies to hide their heads, hiss, and rattle their tails, which can produce a sound somewhat resembling that of a rattlesnake. When they are nervous they tend to twitch their tails. They are considered harmless to humans, but if handled it is common for this species to bite, as well as excrete musk and fecal contents from their cloaca.