The color of the black slug is generally black, but the colouration is very variable and this slug
can even be white. The general trend is for a darker pigmentation the farther north the species
is found. The classification of brown-coloured and rust-coloured "black" slugs is somewhat
disputed; the brown variation is sometimes considered to be a separate species, Arion rufus
(Red Slug). Young specimens of black slug do have a brown colour, which is later lost if and
when the slug changes color to the mature state.The slug covers itself in a thick foul-tasting mucus which serves as both protection against
predators as well as a measure to keep moist. It is somewhat difficult to wash off.The black
slug is mainly nocturnal and avoids exposure to sunlight. It is omnivorous, eating carrion,
fungi, and vegetation (living and decaying). The slug prefers moist conditions, such as lawns,
making it an unwelcome sight for homeowners. This moist environment is essential for the
terrestrial locomotion of the slug to function.The mucus of the slug is highly distasteful to many animals. However, this slug does have
some natural predators, including the hedgehog, badger, shrew, mole, mouse, frog, toad,
snake, carnivorous beetle, and some birds. When picked up or touched, the black slug will
contract to a hemispherical shape and begin to rock from side to side. This defensive
behaviour confuses predators, and is unique in the Arionidae family
can even be white. The general trend is for a darker pigmentation the farther north the species
is found. The classification of brown-coloured and rust-coloured "black" slugs is somewhat
disputed; the brown variation is sometimes considered to be a separate species, Arion rufus
(Red Slug). Young specimens of black slug do have a brown colour, which is later lost if and
when the slug changes color to the mature state.The slug covers itself in a thick foul-tasting mucus which serves as both protection against
predators as well as a measure to keep moist. It is somewhat difficult to wash off.The black
slug is mainly nocturnal and avoids exposure to sunlight. It is omnivorous, eating carrion,
fungi, and vegetation (living and decaying). The slug prefers moist conditions, such as lawns,
making it an unwelcome sight for homeowners. This moist environment is essential for the
terrestrial locomotion of the slug to function.The mucus of the slug is highly distasteful to many animals. However, this slug does have
some natural predators, including the hedgehog, badger, shrew, mole, mouse, frog, toad,
snake, carnivorous beetle, and some birds. When picked up or touched, the black slug will
contract to a hemispherical shape and begin to rock from side to side. This defensive
behaviour confuses predators, and is unique in the Arionidae family
