Snails Snails are fascinating creatures with a variety of habits that allow them to thrive in different environments. Most snails are nocturnal. They prefer to come out during the night or in damp, overcast conditions. These conditions help them avoid dehydration. Their moist bodies are sensitive to sunlight and dry conditions. During the day, they often retreat into their shells. They secrete a layer of mucus called an epiphragm to seal themselves inside and conserve moistur