Strings of Busycon whelk egg capsules commonly wash ashore and desiccate, becoming brittle. As the plant senesces, the galls desiccate and the nematodes undergo anhydrobiosis. Low humidity levels can cause parchment to desiccate. Litema are transient; they may desiccate and crumble or be washed away by heavy rain. The cicada's body and wings desiccate and harden once free of the exuvia. This gelatinous mass helps to protect the eggs by ensuring they do not desiccate. Salting was used by early cultures to help desiccate foods. Conversely, hymenachne is not recorded to survive sites that entirely desiccate. High winds are common and further desiccate the soil. In terms of humidity, the mites desiccate at levels below 20%. Some of the opal has high water content and may desiccate and crack when dried.