Most snakes do not dig -- the behavior and physiological adaptations necessary for digging exist only in a handful of species. Instead, most species use rodent burrows, decayed tree stump holes and rock crevices for shelter. Burrowing snakes travel only a few inches below the surface during the spring, summer and fall; during winter dormancy, they must travel below the frost line.
Snakes hibernate at different depths depending on their species, latitude and elevation. D.C. Rudolph and colleagues investigated the hibernation habits of Louisiana pine snakes (Pituophis ruthveni) and published their results in a 2007 issue of “Journal of Herpetology.” The researchers found that pine snakes rarely hibernated deeper than about 12 inches in their Texas study area. By contrast, their close relatives, northern pine snakes (Pituophis melanoleucus), in New Jersey hibernated at depths between 20 and 42 inches, according to a 1988 study by Joanna Burger and colleagues published in the same journal. The northernmost-occurring snake species in the world -- the common viper (Vipera berus) -- ranges into the arctic circle; to cope with the incredibly cold winters, the viper hibernates approximately 5 feet below the surface.