David Fleetham / Chameleon parrotfish (Scarus chameleon), portrait at night. Sleeping in a mucus bubble secreted from large glands in gill cavity to protect fish from parasites. Fiji.

Tony Wu / Japanese black carpenter ant (Camponotus japonicus) minor workers tending to scale insects (Superfamily Coccoidea). The ant is eating honeydew secreted by the scale insects. Kanagawa, Japan.

Paul Williams / Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park, Sabah, Bo...

Paul Williams / Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park, Sabah, Bo...

Paul Williams / Filming a Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park,...

Paul Williams / Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park, Sabah, Bo...

Paul Williams / Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park, Sabah, Bo...

Paul Williams / Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park, Sabah, Bo...

Paul Williams / Mountain tree shrew (Tupaia montana) feeding on nectar secreted by the endemic Pitcher Plant (Nepenthes kinabaluensis) Montane forests (at 2200m-3000m), slopes of Mt Kinabalu. Kinabalu Park, Sabah, Bo...

Chien Lee / Nymphalid Butterfly (Cupha erymanthis) caterpillar standing guard over a clutch of parasitic wasp pupae that secreted hormones into the caterpillar to guard them after they had c the caterpillars insi...

Chien Lee / Giant Forest Ant (Camponotus gigas) attending to Leaf-footed Bugs (Notobitus sp), providing protection in exchange for honeydew which is secreted at their abdomen, Danum Valley Conservation Area, Saba...

Chien Lee / Giant Forest Ant (Camponotus gigas) attending to Leaf-footed Bugs (Notobitus sp), providing protection in exchange for honeydew which is secreted at their abdomen, Danum Valley Conservation Area, Saba...

Chien Lee / Giant Forest Ant (Camponotus gigas) attending to Leaf-footed Bug (Notobitus sp), providing protection in exchange for honeydew which is secreted at their abdomen, Danum Valley Conservation Area, Sabah...

Solvin Zankl / Ant (Lasius sp) gathering honeydew secreted by aphids on oak tree. Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, June.

Solvin Zankl / Ant (Lasius sp) gathering honeydew secreted by aphids on oak tree. Niedersechsische Elbtalaue Biosphere Reserve, Elbe Valley, Lower Saxony, Germany, June.

Alex Hyde / Cuckoo-spit, a protective foam secreted by the nymph of the Common froghopper (Philaenus spumarius). Devon, UK. June.

Charlie Summers / African elephant (Loxodonta africana), close up of face showing patch of secreted hormone, a sign that the animal is in musth, Ngorongoro Crater, Tanzania, East Africa

Charlie Summers / African elephant (Loxodonta africana) close up of face showing a patch of secreted hormone, a sign that the animal is in musth, Ngorongoro Crater, Tanzania

Chien Lee / Fungus Gnat (Mycetophilidae) secreted sticky threads function as an insect trap, Gunung Mulu National Park, Malaysia

Tim Laman / Fulgorid planthopper (family Fulgoroidea) nymph with body covered in secreted white waxy filaments, to conceal it. Borneo, South east Asia

PREMAPHOTOS / Terrestrial flatworm / Planarian, crawling across rainforest floor, Trinidad Note - Digestive enzymes secreted from mouth, located in centre of body, to begin external digestion

Mark Moffett / Golden Poison Dart Frog (Phyllobates terribilis) close-up of skin pores which poison and mucous are secreted, the secreted batrachotoxins cause irreversible muscle contractions which lead to death, Co...

Ross Hoddinott / Ribwort plantain {Plantago sp} + Cuckoo spit (froth secreted by Planthopper larvae, UK

BERNARD CASTELEIN / Common kingfisher preening wing feathers {Alcedo atthis} Brasschaat, Belgium, Europe. Antibacterial preen oil is secreted at the base of the tail and serves to keep the feathers sterile, elastic and...

GEORGETTE DOUWMA / Violet / bubble raft snail hangs upsidedown from sea surface suspended by raft of mucous coated bubbles secreted by foot {Janthina janthina} Cape, South Africa.

Constantinos Petrinos / Ink secreted by Common reef octopus {Octopus cyaneus} Lembeh, Sulawesi, Indonesia

Ch'ien Lee / Ant (Meranoplus mucronatus) workers guarding planthopper nymphs, from which they take secreted honeydew, Deramakot Forest Reserve, Sabah, Borneo, Malaysia

Tony Wu / Rose petal bubble shell (Hydatina physis) is gathering and arranging freshly secreted eggs on its mantle, prior to attaching the completed egg mass to the sand with a mucous thread, Kanagawa, Japan.

Tony Wu / Rose petal bubble shell (Hydatina physis) gathering and arranging freshly secreted eggs on its mantle, prior to attaching the completed egg mass to the sand with a mucous thread, Kanagawa, Japan.

Morley Read / Slow motion clip of two Yellow-spotted Amazon River Turtle (Podocnemis unifilis) basking on log in river while butterflies fly around them as they seek salt secreted by the turtles nostrils, Rio Tiput...

Morley Read / Slow motion clip of two Yellow-spotted Amazon River Turtle (Podocnemis unifilis) basking on log in river while butterflies fly around them, seeking salt secreted by the turtles nostrils, one turtle di...

Morley Read / Yellow-spotted Amazon River Turtles (Podocnemis unifilis) pair basking on a log while butterflies fly around them seeking salt secreted by the turtles nostrils, one turtle dives into the river, Orella...

Morley Read / Yellow-spotted Amazon River Turtle (Podocnemis unifilis) basking on log in river, while being bothered by a butterfly in search of salt secreted by the turtles nostrils, Rio Tiputini, Orellana provinc...

Nigel Cattlin / Honeydew and soft brown scale insects (Coccus hesperidum) on a banana leaf midrib vein, a house plant.

Nigel Cattlin / Honeydew and soft brown scale insects (Coccus hesperidum) on a banana leaf midrib vein grown as a house plant,