Ingo Arndt / Leopard slug (Limax maximus) mating pair following each other shortly before mating. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male organs, Sw...

Ingo Arndt / Leopard slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male organs, Switzerland

Ingo Arndt / Leopard slug (Limax maximus) climbing and eating at the same time a rope of mucus after mating. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male...

Ingo Arndt / Leopard slug (Limax maximus) climbing and eating at the same time a rope of mucus after mating. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male...

Ingo Arndt / Leopard slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male organs.Switzerland. Sequence...

Ingo Arndt / Leopard slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male organs.Switzerland. Sequence...

Ingo Arndt / Leopard slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male organs.Switzerland. Sequence...

John Cancalosi / Pair of Great grey slugs (Limax maximus) mating, hermaphroditic species, New York, USA, August.

John Cancalosi / Pair of Great grey slugs (Limax maximus) mating, hermaphroditic species, New York, USA, August.

Nick Upton / Young boy and mother holding Leopard / Great grey slugs (Limax maximus) found in garden, Bristol, UK, October 2014. Model released.

Nick Upton / Mother and young boy holding garden snails (Helix aspersa) and Leopard /Great grey slugs (Limax maximus) in their hands, Bristol, garden UK, October 2014. Model released.

Ingo Arndt / Carpathian blue slug (Bielzia coerulans) detail of eye on antenna / Slovakia

Ingo Arndt / Leopard slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites and can be seen here transferring sperm to one another through their male organs.Switzerland. Sequence...

Ingo Arndt / Great Grey Slug (Limax maximus) pair mating while hanging from mucus string, Switzerland

Ingo Arndt / Great Grey Slug (Limax maximus) pair mating, Switzerland

Ingo Arndt / Carpathian Blue Slug (Bielzia coerulans) pneumostome, Slovakia

Ingo Arndt / Carpathian Blue Slug (Bielzia coerulans) skin, Slovakia

Ingo Arndt / Carpathian Blue Slug (Bielzia coerulans), Slovakia

Alex Hyde / Great Grey / Leopard Slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites, and can be seen here transferring sperm to one another through their male organs. Derby...

Alex Hyde / Great Grey / Leopard Slug (Limax maximus) mating, hanging from a rope of mucus. These slugs are hermaphrodites, and can be seen here transferring sperm to one another through their male organs. Photo...

Ingo Arndt / Grey Garden Slug (Derocerasáreticulatum) eggs with hatchlings, Germany

Konrad Wothe / Grey Garden Slug (Deroceras reticulatum), Bavaria, Germany

Gerry Ellis / Grey Garden Slug (Derocerasáreticulatum) using slime to lower itself on to a leaf in an urban garden, Portland, Oregon

Agustin Esmoris / Yellow Garden Slug (Limax flavus), Argentina

Doug Wechsler / Leopard slugs (LImax maximus) pair during courtship, Pennsylvania, USA. September.