Nick Upton / 2020VISION / Black slug (Arion ater), brown form, crawling over patio after rain, with house and garden bench in the background, Wiltshire, UK, July . Property released.

Martin Dohrn / Red forms of Black slug {Arion ater} mating, Northern Italy, Europe

Jason Smalley / Close-up of Slug {Arion ater rufus} feeding on leaf, UK

Nick Upton / Violet ground beetle (Carabus violaceus) attacking a small Grey field slug / Netted slug (Deroceras reticulatum), Hertfordshire garden, UK, August.

Chris Mattison / Black Slug (Arion ater) grey form. Yorkshire, UK, September.

David Woodfall / Black slug feeding on grasses in early morning dew, Gilfach Nature Reserve, Radnorshire Wildlife Trust, Powys, Wales, UK

Piotr Naskrecki / Cup Moth (Limacodidae) caterpillars, Sipaliwini, Surinam

Piotr Naskrecki / Cup Moth (Limacodidae) caterpillars in rainforest, Sipaliwini, Surinam

Rod Williams / Black slug (Arion ater) orange form on leaf, South London, UK, September

Rod Williams / Black slug (Arion ater) orange form on leaf, South London, UK, September

Nick Upton / 2020VISION / Black slug (Arion ater), brown form, crawling over patio after rain, with house and garden bench in the background, Wiltshire, UK, July . Property released.

Alex Hyde / European black slugs (Arion ater) brown variety, mating on leaf litter, Midi-Pyrenees, France. August.

Simon Colmer / Portrait of Black slug, (Arion ater) white form, England, UK

SINCLAIR STAMMERS / Black keel back slug (Limax cinereoniger) Carmarthenshire, Wales, UK

SINCLAIR STAMMERS / Black keel back slug (Limax cinereoniger) Carmarthenshire, Wales, UK

Mark Bowler / Common black slug (Arion ater) orange blonde or white form

Mark Bowler / Common black slug (Arion ater) brown form on lettuce

Mark Bowler / Common black slug (Arion ater) white, orange or blonde form

Mark Bowler / Common black slug (Arion ater) brown form

Mark Bowler / Great black slug (Arion ater) brown form, viewed from above

Mark Bowler / Common black slug (Arion ater) brown form on lettuce

Mark Bowler / Great black slug (Arion ater) brown form

Sebastian Kennerknecht / California Mussel (Mytilus californianus) clusters, Barnacles (Balanus sp), Black Turban Snails (Tegula funebralis), Rockweed (Fucus sp), and Sea Lettuce (Ulva sp) in high tide zone, Santa Cruz, Monte...

Fred Bavendam / Black Velutinid (Coriocella nigra) nudibranch, Manado, Sulawesi, Indonesia

Michele Westmorland / Nudibranch {Jorunna funebris} House Reef at the Jetty, Tufi, Oro Province, Papua New Guinea

Georgette Douwma / Nudibranch {Armina semperi} Rinca, Indonesia

Philippe Clement / Black slug {Arion ater} eating Russula toadstool, Belgium

Philippe Clement / Black slug, orange form {Arion ater} La Brenne, France

GEORGETTE DOUWMA / Great black / Large red slug (Arion ater) Various colour forms: orange-red commonest in south and in gardens while black form prevails in north and upland areas. UK

GEORGETTE DOUWMA / Great black / Large red slug (Arion ater) Various colour forms: orange-red commonest in south and in gardens while black form prevails in north and upland areas. UK

Michael Hutchinson / Large Black Slug {Arion ater} hanging from grass by slime after slipping off the tip, Bristol, UK

Michael Hutchinson / Large Black Slug {Arion ater} on grass seed head, Bristol, UK

Michael Hutchinson / Large Black Slug {Arion ater} attached to grass by slime, Bristol, UK

Michael Hutchinson / Large Black Slug {Arion ater} attached to grass by slime, Bristol, UK

Nigel Bean / Black slugs mating {Arion ater} UK

Nigel Bean / Black slugs mating {Arion ater} UK

Kim Taylor / Black slug, orange form {Arion ater} showing spiracle, UK.

Michael Hutchinson / Black slug, red form {Arion ater} England

Fred Bavendam / Cowry (Phenacovolva gracilis) living on a colony of Black Coral (Antipathes sp), Bali, Indonesia

Fred Bavendam / Cowry (Phenacovolva gracilis) pair living on a colony of Black Coral (Antipathes sp), Bali, Indonesia

PREMAPHOTOS / Black slugs mating {Arion ater} red form, England. Hermaphrodite

Adrian Davies / Black slugs (Arion ater) mating. England, UK, Europe

Fred Bavendam / Black Egg Cowry (Ovula ovum) feeding on a colony of Leather Coral (Sarcophyton sp) on a shallow reef, Manado, North Sulawesi

Adrian Davies / Slugs mating {Arion ater} UK

Michael & Patricia Fogden / Crested Caracara (Caracara cheriway) in dry forest, Guanacaste, Costa Rica

Nick Garbutt / Southern Crested Caracara (Caracara plancus) feeding on a Piranha (Serrasalmus sp.) on the banks of the Pixiam River. Northern Pantanal, Brazil. September

Nick Garbutt / Southern Crested Caracara (Caracara plancus) feeding on a Piranha (Serrasalmus sp.) on the banks of the Pixiam River. Northern Pantanal, Brazil. September

Pete Oxford / Crested Caracara (Caracara cheriway) trio, Rupununi, Guyana

Donald M. Jones / Northern Caracara (Caracara cheriway) banded bird at the edge of a lake, Florida

Charlie Summers / Pair of Northern Crested caracara (Caracara cheriway) courtship preening, Saunders Island, Falkland Islands

Gerrit Vyn / Northern / Crested Caracara (Caracara plancus cheriway) Starr County, Texas, USA, March

Suzi Eszterhas / Southern Caracara (Caracara plancus), Pantanal, Brazil

Thomas Marent / Crested Caracara (Caracara cheriway) feeding on scavenged fish, Venezuela

Tom Vezo / Crested Caracara (Caracara cheriway) adult and juvenile perching in tree, Rio Grande Valley, Texas

Tom Vezo / Crested Caracara (Caracara cheriway) perching on branch, Rio Grande Valley, Texas

Tom Vezo / Crested Caracara (Caracara cheriway) perching on branch, Rio Grande Valley, Texas

Tom Vezo / Crested Caracara (Caracara cheriway) flying, Rio Grande Valley, Texas

Tom Vezo / Crested Caracara (Caracara cheriway) touching down, Rio Grande Valley, Texas

Tom Vezo / Crested Caracara (Caracara cheriway) landing, Rio Grande Valley, Texas

Tom Vezo / American Black Vulture (Coragyps atratus), Crested Caracara (Caracara cheriway), and Turkey Vulture (Cathartes aura) scavenging on carcass, Rio Grande Valley, Texas

Tom Vezo / Northern Caracara (Caracara cheriway) parent feeding chicks in nest, Rio Grande Valley, Texas

Tom Vezo / Northern Caracara (Caracara cheriway) parent feeding chicks at nest in Yucca plant, Rio Grande Valley, Texas