Michael Durham / Townsend's Big-eared Bat (Corynorhinus townsendii) exits a cave in the Derrick Cave complex, a series of lava tubes and lava bubbles, dusk, central Oregon

Michael Durham / Townsend's Big-eared Bat (Corynorhinus townsendii) exits a cave in the Derrick Cave Complex, a series of lava tubes and lava bubbles, central Oregon

Michael Durham / Townsend's Big-eared Bat (Corynorhinus townsendii) exits a cave in the Derrick Cave Complex, a series of lava tubes and lava bubbles, central Oregon

Pete Oxford / Madagascar Flying Fox (Pteropus rufus) group roosting in cave, Berenty Private Reserve, Madagascar

JIM CLARE / Greater spear nosed bat harem {Phyllostomus hastatus} limestone cave, Trinidad

Dietmar Nill / Greater white lined bat flies out of cave {Saccopteryx bilineata} Costa Rica

Dietmar Nill / Pallas' long tongued bat {Glossophaga soricina} flying out of cave entrance, Costa Rica

Doug Wechsler / Spear-nosed bats roosting in cave {Phyllostoma} River Napo, Ecuador, Amazon Basin

Kim Taylor / Insectivorous bats / Naked-backed moustached bat {Pteronotus davyi} emerging from the vertical shaft of a cave at dusk, Trinidad. Digitally enhanced.

Kim Taylor / Insectivorous bats / Naked-backed moustached bat {Pteronotus davyi} emerging from the vertical shaft of cave at dusk, Trinidad.

John Downer / Rousettus fruit bats {Rousettus celebensis} roosting at Goa Lawah bat cave temple, Bali, Indonesia.

John Downer / Worshippers at Goa Lawah bat cave temple, Bali, Indonesia.

Michael Pitts / Bare backed fruit bats flying from cave {Dobsonia sp} Ornozu, Papua New Guinea

Philip Dalton / Lesser Horseshoe Bat roosting in cave (Rhinolophus hipposideros) Somerset, UK

Philip Dalton / Lesser Horseshoe Bat roosting in cave (Rhinolophus hipposideros) Somerset, UK

Philip Dalton / Lesser Horseshoe Bat roosting in cave (Rhinolophus hipposideros) Somerset, UK

Philip Dalton / Lesser Horseshoe Bat roosting in cave (Rhinolophus hipposideros) Somerset, UK

Kim Taylor / Giant / Commerson's leaf-nosed bat {Hipposideros commersoni} in limestone cave, Coastal E. Africa.

Kim Taylor / Whiskered bat {Myotis mystacinus} hibernating in a damp cave, Europe.

Kim Taylor / Giant / Commerson's leaf-nosed bat {Hipposideros commersoni} nursery colony in a limestone cave.

Philippe Clement / Feet of Greater horseshoe bat roosting in cave {Rhinolophus ferrumequinum}

Philippe Clement / Whiskered bat hibernating in cave {Myotis mystacinus} Belgium

Philippe Clement / Whiskered bat hibernating in cave {Myotis mystacinus} Belgium

JIM CLARE / Common cockroaches in bat cave {Blatta orientalis} Trinidad

Kim Taylor / Whiskered bat {Myotis mystacinus} hibernating in a cave, UK.

Pete Oxford / Cave dwelling spider in bat cave (Eumemophoriinae) Madagascar Ankarana Reserve

Pete Oxford / Cave dwelling spider in bat cave (Eumemophoriinae) Madagascar, Ankarana Reserve

Gerry Ellis / Intermediate Roundleaf Bat (Hipposideros larvatus) hanging from cave ceiling, Taman Negara National Park, Malaysia

Gerry Ellis / Intermediate Roundleaf Bat (Hipposideros larvatus) hanging from cave ceiling, Taman Negara National Park, Malaysia

Gerry Ellis / Intermediate Roundleaf Bat (Hipposideros larvatus) group hanging from cave ceiling, Malaysia

Solvin Zankl / {Microchiroptera} bat flying from cave, Bahamas

Elizabeth White / Common vampire bat {Desmodus rotundus} in cave, Nigaragua

Nick Upton / Trinidadian funnel-eared bats {Natalus tumidirostris haymani} and Greater spear nosed bats {Pyllostomus hastatus} in cave complex, Trinidad.

Pete Oxford / Tongue-clicking bats (Rousettus madagascariensis) in bat cave, Madagascar

John Downer / Rousettus fruit bats at Goa Lawah bat cave temple, Bali. Indonesia.

John Downer / Worshippers at Goa Lawah bat cave temple, Bali, Indonesia.

John Downer / Rousettus fruit bats at Goa Lawah bat cave temple, Bali. Indonesia.

Dietmar Nill / Lesser horseshoe bat roosting on stalactite in cave, Germany {Rhinolophus hipposideros}

JIM CLARE / Greater spear nosed bat harem {Phyllostomus hastatus} inside Limestone cave, Trinidad

Hans Christoph Kappel / Man-made entrance to bat cave, Germany

Jose B. Ruiz / Serotine bats (Eptesicus serotinus) at roost in cave. Spain

Ingo Arndt / Ingo Arndt at work taking pictures of hibernating bats in cave, Geramny, picture taken by Rolf Klenk

Ingo Arndt / Greater Mouse-eared Bat (Myotis myotis) group hibernating in cave, Germany

Ingo Arndt / Greater Mouse-eared Bat (Myotis myotis) group hibernating in cave, Germany

Ingo Arndt / Greater Mouse-eared Bat (Myotis myotis) group hibernating in cave, Germany

Ingo Arndt / Greater Mouse-eared Bat (Myotis myotis) group hibernating in cave, Germany

Ingo Arndt / Greater Mouse-eared Bat (Myotis myotis) group hibernating in cave, Germany

Christian Ziegler / Entrance to a bat cave, Bastimentos Marine National Park, Bocas del Toro, Panama

Christian Ziegler / Jamaican Fruit-eating Bat (Artibeus jamaicensis) white morph roosting in cave, Bocas del Toro, Panama

Christian Ziegler / Jamaican Fruit-eating Bat (Artibeus jamaicensis) group roosting in a cave, Bocas del Toro, Panama

Christian Ziegler / Jamaican Fruit-eating Bat (Artibeus jamaicensis) group roosting in a cave, Bocas del Toro, Panama

Phil Chapman / Cave racer snake {Elaphe taeniura} predating Diadem roundleaf bat, Sarawak, Borneo, Malaysia

Kevin Schafer / Multiple species of bats emerge from a limestone cave, Calakmul Biosphere Reserve, Mexico

Kim Taylor / Daubenton's bat (Myotis daubentonii) hibernating in a sandstone cave, Surrey, England

Barry Mansell / Cave bat {Myotis velifer} flying at night, Arizona, USA

Premaphotos / Beetles (Zophobas sp) feeding amongst bat guano in Tingo Maria cave, Peru

Phil Savoie / Little brown bat (Myotis lucifungus) hibernating in cave, covered in water droplets. Blanford, Connecticut, USA

Michael Durham / Bat gate at entrance to Gold Stake Mine in Coleville National Forest, Washington

Nick Upton / Camerman Jim Clare on location in Trinidad, using an infra red sensitive camera to record bat behaviour in cave and wearing a mask

Premaphotos / Giant cockroach (Blaberus giganteus) amongst bat droppings in a cave full of roosting bats in rainforest, Trinidad

Jose B. Ruiz / Greater mouse eared bat flying {Myotis myotis} Spain

Jose B. Ruiz / Greater mouse eared bat flying {Myotis myotis} Spain

Jose B. Ruiz / Greater mouse eared bat flying {Myotis myotis} Spain

Jose B. Ruiz / Greater horseshoe bat flying {Rhinolophus ferrumequinum} Spai

Jose B. Ruiz / Greater mouse eared bat flying {Myotis myotis} Spain

Jose B. Ruiz / Greater mouse eared bat flying {Myotis myotis} Spain

Hans Christoph Kappel / Man-made entrance to bat cave (Chiroptera) Germany