Some Snails Can Hibernate for Three Years or More

Much like many snowbirds (human and avian) who travel south for winter, most snails have a tough time handling cold weather. Snails often enter prolonged states of hibernation, sealing off their shells with an insulating calcified membrane called an epiphragm. While many snails emerge from hibernation after a few months, certain species can hibernate for years at a time.

This revelation came to light in 1846, when a snail of the species Eremina desertorum — which was believed to be dead — was taken from Egypt to be displayed at the British Museum. More than three years later, curators noticed that the snail had woken up after an impressively prolonged rest. Snails may also enter a state of estivation, which, unlike hibernation, is done to survive in extremely hot environments. This process, too, can last for at least three years.