Juergen Freund / Spectacled flying fox (Pteropus conspicillatus) casualty of paralytic tick (Ixodes holocyclus) bite being cared for on site of colony by Jenny Mclean, North Queensland, Australia, November 2012

Anup Shah / Celebes / Black crested macaque (Macaca nigra) juvenile feeding on a fruit whilst lying on back, Tangkoko National Park, Sulawesi, Indonesia.

Piotr Naskrecki / Flannel Moth (Megalopygidae) caterpillar, Sipaliwini, Surinam

Piotr Naskrecki / Goliath Bird-eating Spider (Theraphosa blondi), Sipaliwini, Surinam

Piotr Naskrecki / Goliath Bird-eating Spider (Theraphosa blondi) in rainforest, Sipaliwini, Surinam

Piotr Naskrecki / Goliath Bird-eating Spider (Theraphosa blondi) in leaf litter, Guyana

Piotr Naskrecki / Goliath Bird-eating Spider (Theraphosa blondi), Surinam

Suzi Eszterhas / Sumatran Forest Elephant (Elephas maximus sumatranus) tail, Way Kambas Elephant Training Center, Sumatra, Indonesia

Pete Oxford / Goliath Bird-eating Spider (Theraphosa blondi), Rewa River, Guyana

Pete Oxford / Goliath Bird-eating Spider (Theraphosa blondi), Rewa River, Guyana

Pete Oxford / Goliath Bird-eating Spider (Theraphosa blondi) on tree trunk, Rewa River, Guyana

Pete Oxford / Goliath Bird-eating Spider (Theraphosa blondi) on tree trunk, Rewa River, Guyana

Pete Oxford / Moth caterpillar with well developed appendages with urticating hairs, Rewa River, Guyana

Donald M. Jones / White-tailed Deer (Odocoileus virginianus) hair on a barbed wire fence, western Montana

Stephen Belcher / Sumatran Rhinoceros (Dicerorhinus sumatrensis) skin showing hairs, Way Kambas National Park, Sumatra, Indonesia

Piotr Naskrecki / Mole Cricket (Gryllotalpa sp) group used as bait for fishing, lodged in boy's hair, Rio Kapatchez, Guinea

Petra Wegner / Domestic dog, 6 week old silver Miniature Poodle puppy looking up at apricot Miniature Poodle

Petra Wegner / Domestic dogs, Black and Apricot Miniature Poodles sitting in a line

Suzi Eszterhas / Spotted Hyena (Crocuta crocuta) 4 month old cub with wildebeest hair in mouth, Masai Mara National Reserve, Kenya

Piotr Naskrecki / Pollen Katydid (Kawanaphila sp) covered with fine, soft hair making them ideal pollinators, Australia

Pete Oxford / White-lipped Peccary (Tayassu pecari) raising hair on back in an aggressive response, Brazil

Michael & Patricia Fogden / Brown-throated Three-toed Sloth (Bradypus variegatus) close-up of symbiotic green algae in hair, 20 times magnification, Central America

Michael & Patricia Fogden / Hair-footed Pygmy Gerbil (Gerbillurus tytonis) in desert under spiny Nara thicket, Namib Desert dunes Namibia

Michael & Patricia Fogden / Brown-throated Three-toed Sloth (Bradypus variegatus) female carrying baby, symbiotic green algae growing in hair, rainforest, Panama

Tui De Roy / Flightless Cormorant (Phalacrocorax harrisi) endemic pair, showing heavily built head and hair-like feathers, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Tui De Roy / Flightless Cormorant (Phalacrocorax harrisi) endemic pair, showing heavily built head and hair-like feathers, Punta Espinosa, Fernandina Island, Galapagos Islands, Ecuador

Norbert Wu / Brown-throated Three-toed Sloth (Bradypus variegatus) with symbiotic algae growing in hair, rainforest ecosystem, Panama

Norbert Wu / Brown-throated Three-toed Sloth (Bradypus variegatus) with symbiotic algae growing in hair, rainforest ecosystem, Panama

Norbert Wu / Stareye Hermit (Dardanus venosus) eyes on stalks, hair on arms used for sensing food in sand, Caribbean

Norbert Wu / Brown-throated Three-toed Sloth (Bradypus variegatus) gentle and slow-moving with symbiotic algae growing in hair, rainforest ecosystem, Panama

Norbert Wu / Brown-throated Three-toed Sloth (Bradypus variegatus) gentle and slow-moving with symbiotic algae growing in their hair, rainforest ecosystem, Panama

Norbert Wu / Brown-throated Three-toed Sloth (Bradypus variegatus) gentle and slow-moving, symbiotic algae in hair, Panama Rainforest

Norbert Wu / Brown-throated Three-toed Sloth (Bradypus variegatus) gentle and slow-moving with symbiotic algae growing in their hair, rainforest ecosystem, Panama

Mark Moffett / Goliath Bird-eating Spider (Theraphosa blondi) with researcher's gloved hand showing defensive behavior where spider breaks off toxic hairs from abdomen with hind legs, French Guiana

Mitsuaki Iwago / Domestic Cat (Felis catus) grey kitten in defensive posture with back arched and hair raised

Piotr Naskrecki / Goliath Bird-eating Spider (Theraphosa blondi) in defensive posture, Suriname

Hiroya Minakuchi / Southern Right Whale (Eubalaena australis) hair on chin and upper jaw, Valdes Peninsula, Argentina

Hiroya Minakuchi / Southern Right Whale (Eubalaena australis) hair on chin and upper jaw, Valdes Peninsula, Argentina

Hiroya Minakuchi / Southern Right Whale (Eubalaena australis) hair on its chin and upper jaw, Valdes Peninsula, Argentina

Suzi Eszterhas / Chimpanzee (Pan troglodytes) aggressive male with erect hair, western Uganda

Piotr Naskrecki / Flannel Moth (Megalopygidae) caterpillar, Sipaliwini, Surinam

Suzi Eszterhas / Brown-throated Three-toed Sloth (Bradypus variegatus) six month old orphan baby with red hair from treatment for mange weighed by sanctuary worker Claire Trimer, Aviarios Sloth Sanctuary, Costa Rica

Pete Oxford / Moth caterpillar with well developed appendages with urticating hairs, Rewa River, Guyana

Ingo Arndt / Caribou (Rangifer tarandus) hair washed ashore on river bank during migration, Arctic National Wildlife Refuge, Alaska

Vincent Grafhorst / Malagasy girls doing each others hair in smoky area, Bekopaka, western Madagascar

Vincent Grafhorst / Malagasy girls doing each others hair in smoky area, Bekopaka, western Madagascar

Pete Oxford / Ocelot (Leopardus pardalis) fur and goat hair on chaps worn by Chagra cowboys at a hacienda during the annual overnight cattle round-up, Andes Mountains, Ecuador

Mark Moffett / Doug Yu, an ecologist, cuts Wasps and Killer Bees from Mark Moffett's hair, Devil's Garden, Manu, Peru