Snail slime (mucopolysaccharide) 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. 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. The slime trail that a land gastropod leaves behind is often visible as a silvery track on surfaces such as stone or concrete. Description Mucus is a gel consisting of a polymer network that functions as a protective layer for the integument and mucosal surfaces of both elementary animals and mammals. The mucus of gastropods is not only used as a coating to cover the surfaces on which the snail crawls and a coating to cover the exposed soft parts of the body but also sometimes to allow a resting snail to adhere passively to surfaces, such as rock, making a temporary sealing structure called the epiphragm. Mucus is produced by a large gland located below the snail's mouth. The foot of gastropods is covered with a thin layer of this mucus, which is used for a variety of functions, including locomotion, adherence, lubrication, repulsing predators, recognizing other snails, following a trail to a known destination and during reproduction. The discharge looks like a gel and it contains approximately 91 to 98% water by weight, depending on the species, combined with a small amount of high molecular weight glycoproteins (Denny, 1984). In Cornu aspersum, these glycoproteins reach weights of 82, 97 and 175 kDa. Locomotion Locomotion in snails comes from a series of muscle contractions called pedal waves and relaxations called inter waves. The waves created help propel the snail forward whilst pushing the thin layer of mucus used as lubrication, behind them. In an Experimental Biology article, research has been presented showing that each wave is indeed creating a propulsive force using the mucus to reduce resistance.