Will Burrard-Lucas / Black and white image of African elephant (Loxodonta africana) mud bathing, Tsavo Conservation Area, Kenya. Editorial use only.

Denis-Huot,Denis-Huot / Hippopotamus (Hippopotamus amphibius) males in a muddy pond, aerial view, Rwindi national park, Democratic Republic of Congo. Vulnerable species.

Denis-Huot / African buffalo (Syncerus caffer) male covered with mud after mud bathing, Nakuru National Park, Kenya

Mark Carwardine / Stephen Fry and Mark Carwadine after a mud bath in Borneo, filming for BBC TV series 'Last Chance to See', March 2009

Christophe Courteau / African Buffalo {Sincerus caffer} bull taking a mud bath, Okavango Delta, Botswana.

Tui De Roy / Volcan Alcedo giant tortoises (Chelonoidis nigra vandenburghi) wallowing in rain pools on caldera floor, possibly for thermoregulation or detering parasites, with sulphur fumaroles in background, Alce...

Ben Osborne / African elephant (Loxodonta africana) splashes mud with his foot. Savuti, Northern Botswana. Taken on location for BBC Planet Earth series, 2005

Andy Rouse / African elephant (Loxodonta africana) bull spraying mud at camera, Savute, Botswana (non-ex)

Andy Rouse / African elephant (Loxodonta africana) spraying water from trunk, bathing, Marakele NP, South Africa

Anup Shah / Low angle Warthog {Phacochoerus aethiopicus} about to wallow in mud, Serengeti NP, Tanzania

Tony Heald / African elephant {Loxodonta africana} kicking up white mud (Calcrete and water) Etosha national park, Namibia.

Chris O'Reilly / Red deer stag shaking off mud after wallowing {Cervus elaphus} Scotland, UK

Jane Burton / African Clawed Toad (Xenopus laevis) emerging from mud, Africa.

Gerry Ellis / African Elephant (Loxodonta africana) orphan called Isholta, five weeks old, playing in mud bath, David Sheldrick Wildlife Trust, Tsavo East National Park, Kenya

Richard Du Toit / African elephant sprays itself with mud {Loxodonta africana} Linyanti, Botswana, Southern Africa. The mud-pack, when dry, forms a hard crust that deters insect attacks.

John Cancalosi / African elephants bathing {Loxodonta africana} South Africa

Gerry Ellis / African Elephant (Loxodonta africana) orphan called Natumi, charging and playing in mud bath, David Sheldrick Wildlife Trust, Tsavo East National Park, Kenya

Gerry Ellis / African Elephant (Loxodonta africana) orphans, Nyiro and Lewa in mud bath, David Sheldrick Wildlife Trust, Tsavo East National Park, Kenya

Yashpal Rathore / African elephant (Loxodonta africana) newborn calf and mother within herd, mud bathing. Chobe River, Chobe National Park, Botswana.

Karine Aigner / African wild dog (Lycaon pictus) covered in mud after bathing in it. Zimbabwe.

Karine Aigner / African wild dogs (Lycaon pictus) watching an African elephant (Loxodonta africana) bathe in mud. Zimbabwe.

Will Burrard-Lucas / Black and white image of African elephant (Loxodonta africana) herd mud bathing, some with extremely long tusks, Tsavo Conservation Area, Kenya. Editorial use only.

Sean Viljoen / Slow motion clip of an African elephant (Loxodonta africana) mud bathing at waterhole, Mababe, Botswana.

Sean Viljoen / Slow motion clip of an African elephant (Loxodonta africana) mud bathing at waterhole, Mababe, Botswana.

Sean Viljoen / Slow motion clip of an African elephant (Loxodonta africana) mud bathing at a waterhole, Mababe, Botswana.

Sean Viljoen / Slow motion clip of an African elephant (Loxodonta africana) mud bathing at a waterhole, Mababe, Botswana.

Sean Viljoen / Slow motion clip of an African elephant (Loxodonta africana) mud bathing at a waterhole, Mababe, Botswana.

Sean Viljoen / Slow motion clip of an African elephant (Loxodonta africana) mud bathing at a waterhole, Mababe, Botswana.

Sean Viljoen / Family of African elephants (Loxodonta africana) mud bathing at a waterhole, Mababe, Botswana.

Sean Viljoen / Family of African elephants (Loxodonta africana) mud bathing at a waterhole, Mababe, Botswana.

Denis-Huot / African elephant (Loxodonta africana) having a bath at a water hole, Tsavo East National Park, Kenya. August.

Denis-Huot / Warthog (Phaecochoerus aethiopicus) male lying in a muddy puddle, Nairobi National Park, Kenya. April.

Denis-Huot / Hippopotamus (Hippopotamus amphibius) male covered in mud, Masai-Mara Game Reserve, Kenya. March.

Cyril Ruoso / African elephant (Loxodonta africana) bathing, Hwange National Park, Zimbabwe.

Eric Baccega / African elephant (Loxodonta africana) herd drinking and bathing in mud at a waterhole, Hwange National Park, Zimbabwe

Yva Momatiuk & John Eastcott / African Elephant (Loxodonta africana) mud bathing, Etosha National Park, Namibia

Yva Momatiuk & John Eastcott / African Elephant (Loxodonta africana) mud bathing, Etosha National Park, Namibia

Yva Momatiuk & John Eastcott / African Elephant (Loxodonta africana) sub-adults mud bathing, Etosha National Park, Namibia

Denis-Huot / Hippopotamus (Hippopotamus amphibius), mud bathing, Chobe National park, Botswana

Pete Oxford / White Rhinoceros (Ceratotherium simum) mud bathing, South Africa

Ann & Steve Toon / Warthog (Phacochoerus aethiopicus) mother and young mud bathing, Mkhuze Game Reserve, KwaZulu-Natal, South Africa, June

Theo Allofs / African Elephant (Loxodonta africana) orphan juveniles mud bathing, David Sheldrick Wildlife Trust, Nairobi, Kenya

Theo Allofs / African Elephant (Loxodonta africana) orphan juveniles mud bathing, David Sheldrick Wildlife Trust, Nairobi, Kenya

Roland Seitre / Black Rhinoceros (Diceros bicornis) mud bathing, Zimbabwe

Denis-Huot / Male African buffalo (Syncerus caffer) having a mud bath, flinging mud, Meru National Park, Kenya. May.

Richard Du Toit / African Elephant (Loxodonta africana) mud bathing, Chobe National Park, Botswana

Richard Du Toit / African Elephant (Loxodonta africana) scratching ear after mud bath, Kruger National Park, South Africa

Axel Gomille / Asian elephant (Elephas maximus), wild male taking mud-bath, Nagarhole National Park, South India.

Ann & Steve Toon / African elephants (Loxodonta africana) drinking and bathing at Hapoor waterhole, Addo Elephant National Park, Eastern Cape, South Africa, February

Anup Shah / African elephants wallowing and playing in mud at a dried up waterhole (Loxodonta africana). Maasai Mara National Reserve, Kenya. Feb 2012.

Anup Shah / African elephants (Loxodonta africana) wallowing and playing in mud at a dried up waterhole. Maasai Mara National Reserve, Kenya. Feb 2012.

Anup Shah / African elephant (Loxodonta africana) juvenile covered in mud after wallowing. Maasai Mara National Reserve, Kenya. Feb 2012.

Roland Seitre / Sumatran rhinoceros (Dicerorhinus sumatrensis) female mud bathing at captive breeding facility at Cincinati Zoo, USA. Native to Sumatra, Borneo and the Malay Penninsula. Critically endangered species...

Anup Shah / African Elephant (Loxodonta africana) calf wallowing in mud, Masai Mara National Reserve, Kenya

Lou Coetzer / Bull African elephant (Loxodonta africana) mud bathing, Chobe River, Botswana, November, Vulnerable species.

Tui De Roy / Galapagos Giant Tortoise (Chelonoidis nigra porteri) taking a mud bath, El Chato Tortoise Reserve, Santa Cruz Island, Ecuador

Michele Westmorland / Galapagos giant tortoises (Chelonoidis nigra) taking mud bath, Galapagos Islands. Vulnerable species.

Michele Westmorland / Galapagos giant tortoises (Chelonoidis nigra) taking mud bath, Galapagos Islands. Vulnerable species.

Michele Westmorland / Tourists viewing Galapagos giant tortoises (Chelonoidis nigra) taking mud bath, Galapagos Islands, January 2012. Model released.

Michele Westmorland / Galapagos giant tortoises, (Chelonoidis nigra) taking mud bath, Galapagos Islands, vulnerable species.

Michele Westmorland / Galapagos giant tortoises, (Chelonoidis nigra) taking mud bath, Galapagos Islands, vulnerable species.

Winfried Wisniewski / African Elephant (Loxodonta africana) taking a mudbath at a watering hole, Hwange National Park, Zimbabwe

Denis-Huot / African buffalo (Syncerus caffer) male taking a mud bath, Masai-Mara Game Reserve, Kenya

Cyril Ruoso / Sumatran Rhinoceros (Dicerorhinus sumatrensis) female in waterhole, Sumatran Rhino Sanctuary, Way Kambas National Park, Sumatra, Indonesia

Cyril Ruoso / Sumatran Rhinoceros (Dicerorhinus sumatrensis) female in waterhole, Sumatran Rhino Sanctuary, Way Kambas National Park, Sumatra, Indonesia

D. Parer & E. Parer-Cook / Little Blue Penguin (Eudyptula minor) being washed after rescue from collapsed nest burrow, Phillip Island, Australia

Denis-Huot / Hippo (Hippopotamus amphibius) male drinking after mud bath, Masai-Mara Game Reserve, Kenya. Vulnerable species.

Denis-Huot / Hippo (Hippopotamus amphibius) male yawning during a mud bath, Masai-Mara Game Reserve, Kenya. Vulnerable species.

Denis-Huot / Hippo (Hippopotamus amphibius) male in mud bath, Masai-Mara Game Reserve, Kenya. Vulnerable species.

Denis-Huot / Hippo (Hippopotamus amphibius) male yawning during a mud bath, Masai-Mara Game Reserve, Kenya. Vulnerable species.

Denis-Huot / African buffalo (Syncerus caffer) covered in mud during mud bath bath, Masai-Mara game reserve, Kenya

Gavin Hellier / The Blue Lagoon, Iceland's most famous tourist attraction is located among the black lava flows outside Reykjavik. The geothermal spa owes its existence to the Svartsengi geothermal power plant powere...

Gavin Hellier / The Blue Lagoon, Iceland's most famous tourist attraction is located among the black lava flows outside Reykjavik. The geothermal spa owes its existence to the Svartsengi geothermal power plant powere...

Tony Heald / African elephant (Loxodonta africana) baby wallowing in mud, Mana Pools National Park, Zimbabwe October 2012

Christophe Courteau / Spotted Hyaena (Crocutta crocutta) enjoying a mud bath at waterhole, Okavango Delta, Botswana

Christophe Courteau / African Buffalo (Syncerus caffer) head portrait after mud bath, Okavango Delta, Botswana

Oriol Alamany / African buffalo (Syncerus caffer) mud bathing in a dry riverbed, Kruger National Park, Transvaal, South Africa, September.

Tui De Roy / Volcan Alcedo giant tortoise(Chelonoidis nigra vandenburghi) in muddy water, possibly for thermoregulation or to deter parasites, Isabela Island, Galapagos

Tui De Roy / Volcan Alcedo giant tortoises (Chelonoidis nigra vandenburghi) wallowing in muddy pool, possibly for thermoregulation or to deter parasites, and misty clouds over the mountain, Isabela Island, Galapag...

Tui De Roy / Volcan Alcedo giant tortoises (Chelonoidis nigra vandenburghi) wallowing in muddy water, possibly for thermoregulation or to deter parasites, Alcedo Volcano, Isabela Island, Galapagos

Tony Heald / Black rhinoceros (Diceros bicornis) male wallowing in water, Etosha National Park, Namibia

Roland Seitre / African Elephant (Loxodonta africana) adult and baby, wet with rain, playing in red dust. Tsavo National Park, Kenya, 2009.

Roland Seitre / African Elephant (Loxodonta africana) juvenile and baby, wet with rain, playing in red dust. Tsavo National Park, Kenya, 2009.

Roland Seitre / African Elephant (Loxodonta africana) juvenile and baby, wet with rain, playing in red dust. Tsavo National Park, Kenya, 2009.

Roland Seitre / African Elephant (Loxodonta africana) juvenile and baby , wet with rain, playing in red dust. Tsavo National Park, Kenya, 2009.

Ben Osborne / Aerial view of African elephants (Loxodonta african) bathing in mud on the banks of the Linyanti River, Botswana. Taken on location for BBC Planet Earth series, 2005

Ben Osborne / Aerial view of African elephants (Loxodonta african) bathing in mud on the banks of the Linyanti River, Botswana. Taken on location for BBC Planet Earth series, 2005

Ben Osborne / African elephant (Loxodonta africana) bull splashes muddy water at a waterhole in Savuti, Northern Botswana. Taken on location for BBC Planet Earth series, 2005

Ben Osborne / African elephant (Loxodonta africana) bull splashes muddy water at a waterhole in Savuti, Northern Botswana. Taken on location for BBC Planet Earth series, 2005

Ernie Janes / Pere David's Deer (Elaphurus davidianus) stag wallowing in mud, captive, extinct in the wild

Lassi Rautiainen / Brown bear (Ursus arctos) wallowing in mud in woodland wetlands, Kuhmo, Finland, July

Lassi Rautiainen / Brown bear (Ursus arctos) wallowing in mud in woodland wetlands, Kuhmo, Finland, July

Anup Shah / African elephants (Loxodonta africana) digging out a mud wallow, with calf aged 3-6 months, Masai Mara National Reserve, Kenya. February

Edwin Giesbers / Wild boar (Sus scrofa) wallowing / bathing, the Netherlands, April