Why do many land snails become inactive during droughts?

Land snails become inactive during droughts primarily to avoid desiccation, a critical survival strategy for these mollusks in terrestrial environments. This state of dormancy, often referred to as estivation, allows them to conserve moisture and energy when environmental conditions are unfavorable.123

To protect themselves, land snails employ several specific adaptations:

• Shell Protection: Many species retreat into their shells and secrete a protective membrane across the aperture, known as an epiphragm. This seal, composed of mucus and sometimes lime, effectively minimizes water loss.12
• Behavioral Adjustments: Snails may seek out damp niches, stay in areas of high moisture, or burrow into the soil to escape dry conditions.12
• Specialized Structures: Some prosobranchs use an operculum to seal their shells, while others in arid regions have developed breathing tubes to facilitate gas exchange while remaining sealed.1
• Extended Dormancy: Certain species, such as those in the genus Sonorella, can remain dormant for years between rainfall events.1