Many frog species hibernate during winter, and some estivate, which is similar to hibernation. Aquatic frogs usually hibernate underwater, while terrestrial frogs hibernate on land by burrowing into the soil below the frost line. Other terrestrial species seek out crevices in rocks or logs, or even burrow under leaf litter.
Estivation is a self-induced dormant state in which the frog burrows into the soil, sheds some of its skin and forms a cocoon around itself, with only its nostrils exposed to allow it to breathe. When its estivation period ends, the frog sheds the cocoon and emerges from the soil to resume active life.