The body of the slug is elongated and measures between 1 and 15 cm depending on the species. The head has four antennae and a mouth; the upper antennae have eyes at their ends, which are also tactile and olfactory organs. The mucus, or liquid secretion that coats its body, acts as a humectant and facilitates movement. Slugs are not very mobile. It can travel, under optimal conditions, between 4 m and 7 m in a single day. A slug can eat up to half its weight in one night, they are nocturnal being