Ashley Cooper / Midge bites on a man

Tim Laman / Russell Laman, with itchy arms after falling in muddy trail. Gunung Palung National Park, Borneo. August 2010 Model released.

Roger Powell / Reindeer (Rangifer tardus) rubbing its velvet antlers on vegetation. Porsanger interior, Finmark, Norway, June.

Dave Watts / Common Wombat (Vombatus ursinus) adult scratching, Tasmania.

Christophe Courteau / Walrus (Odobenus rosmanus) scratching, Poolpynten, Svalbard, Norway, June 2012.

Solvin Zankl / Bat-eared fox (Otocyon megalotis) scratching face, Namib-Naukluft National Park, Namib Desert, Namibia.

Jabruson / Young wild Chimpanzee (Pan troglodytes schweinfurthii) Tongo, Virunga National Park, Kivu, Democratic Republic of Congo

Eric Baccega / Male Steller sea lion (Eumetopias jubatus) scratching, with a group of females hauled out at a rookery, Prince Rupert, British Columbia, Canada, June.

Eric Baccega / Male Steller sea lion (Eumetopias jubatus) scratching, with a group of females hauled out at a rookery, Prince Rupert, British Columbia, Canada, June.

Mark Taylor / Black-and-white tuxedo male kitten, 'Tuxie' aged 3 months, using a scratching post.

Vincent Grafhorst / Lechwe (Kobus leche) male biting its itchy back, Moremi Game Reserve, Okavango Delta, Botswana

PREMAPHOTOS / Human head louse {Pediculus humanus capitis} amongst hair, UK

Mike Potts / Grey seal {Halichoerus grypus} scratching face, Bardsey island, Gwynedd, Northern Wales, UK

Pete Oxford / Orangutan (Pongo pygmaeus) scratching head, found in Borneo and Sumatra

Jami Tarris / Japanese Macaque (Macaca fuscata) scratching, Jigokudani, Nagano, Japan