Snail slime

Snail slime is a kind of mucus (an external bodily secretion) produced by snails, which are gastropod mollusks. Land snails and slugs both produce mucus, as does every other kind of gastropod, from marine, freshwater, and terrestrial habitats. The reproductive system of gastropods also produces mucus internally from special glands.

Chemically, the mucus produced by land-living gastropodes belongs to the class of glycosaminoglycans (previously called mucopolysaccharides). Externally, one kind of mucus is produced by the foot of the gastropod and is usually used for crawling. The other kind of external mucus has evolved to coat the external parts of the gastropod's body; in land species, this coating helps prevent desiccation of the exposed soft tissues. The foot mucus of a gastropod has some of the qualities of glue and some of the qualities of a lubricant, allowing land snails to crawl up vertical surfaces without falling off.^[1]

The slime trail that a land gastropod leaves behind is often visible as a silvery track on surfaces such as stone or concrete.